t0025-crlf-auto.sh: use the $( ... ) construct for command substitution

The Git CodingGuidelines prefer the $(...) construct for command
substitution instead of using the backquotes `...`.

The backquoted form is the traditional method for command
substitution, and is supported by POSIX.  However, all but the
simplest uses become complicated quickly.  In particular, embedded
command substitutions and/or the use of double quotes require
careful escaping with the backslash character.

The patch was generated by:

for _f in $(find . -name "*.sh")
do
   sed -i 's@`\(.*\)`@$(\1)@g' ${_f}
done

and then carefully proof-read.

Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
Reviewed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t0025-crlf-auto.sh

@@ -19,9 +19,9 @@ test_expect_success setup '
 
 	git commit -m initial &&
 
-	one=`git rev-parse HEAD:one` &&
-	two=`git rev-parse HEAD:two` &&
-	three=`git rev-parse HEAD:three` &&
+	one=$(git rev-parse HEAD:one) &&
+	two=$(git rev-parse HEAD:two) &&
+	three=$(git rev-parse HEAD:three) &&
 
 	echo happy.
 '
@@ -33,9 +33,9 @@ test_expect_success 'default settings cause no changes' '
 
 	! has_cr one &&
 	has_cr two &&
-	onediff=`git diff one` &&
-	twodiff=`git diff two` &&
-	threediff=`git diff three` &&
+	onediff=$(git diff one) &&
+	twodiff=$(git diff two) &&
+	threediff=$(git diff three) &&
 	test -z "$onediff" -a -z "$twodiff" -a -z "$threediff"
 '
 
@@ -48,7 +48,7 @@ test_expect_success 'crlf=true causes a CRLF file to be normalized' '
 
 	# Note, "normalized" means that git will normalize it if added
 	has_cr two &&
-	twodiff=`git diff two` &&
+	twodiff=$(git diff two) &&
 	test -n "$twodiff"
 '
 
@@ -60,7 +60,7 @@ test_expect_success 'text=true causes a CRLF file to be normalized' '
 
 	# Note, "normalized" means that git will normalize it if added
 	has_cr two &&
-	twodiff=`git diff two` &&
+	twodiff=$(git diff two) &&
 	test -n "$twodiff"
 '
 
@@ -72,7 +72,7 @@ test_expect_success 'eol=crlf gives a normalized file CRLFs with autocrlf=false'
 	git read-tree --reset -u HEAD &&
 
 	has_cr one &&
-	onediff=`git diff one` &&
+	onediff=$(git diff one) &&
 	test -z "$onediff"
 '
 
@@ -84,7 +84,7 @@ test_expect_success 'eol=crlf gives a normalized file CRLFs with autocrlf=input'
 	git read-tree --reset -u HEAD &&
 
 	has_cr one &&
-	onediff=`git diff one` &&
+	onediff=$(git diff one) &&
 	test -z "$onediff"
 '
 
@@ -96,7 +96,7 @@ test_expect_success 'eol=lf gives a normalized file LFs with autocrlf=true' '
 	git read-tree --reset -u HEAD &&
 
 	! has_cr one &&
-	onediff=`git diff one` &&
+	onediff=$(git diff one) &&
 	test -z "$onediff"
 '
 
@@ -108,9 +108,9 @@ test_expect_success 'autocrlf=true does not normalize CRLF files' '
 
 	has_cr one &&
 	has_cr two &&
-	onediff=`git diff one` &&
-	twodiff=`git diff two` &&
-	threediff=`git diff three` &&
+	onediff=$(git diff one) &&
+	twodiff=$(git diff two) &&
+	threediff=$(git diff three) &&
 	test -z "$onediff" -a -z "$twodiff" -a -z "$threediff"
 '
 
@@ -123,9 +123,9 @@ test_expect_success 'text=auto, autocrlf=true _does_ normalize CRLF files' '
 
 	has_cr one &&
 	has_cr two &&
-	onediff=`git diff one` &&
-	twodiff=`git diff two` &&
-	threediff=`git diff three` &&
+	onediff=$(git diff one) &&
+	twodiff=$(git diff two) &&
+	threediff=$(git diff three) &&
 	test -z "$onediff" -a -n "$twodiff" -a -z "$threediff"
 '
 
@@ -137,7 +137,7 @@ test_expect_success 'text=auto, autocrlf=true does not normalize binary files' '
 	git read-tree --reset -u HEAD &&
 
 	! has_cr three &&
-	threediff=`git diff three` &&
+	threediff=$(git diff three) &&
 	test -z "$threediff"
 '
 
@@ -148,7 +148,7 @@ test_expect_success 'eol=crlf _does_ normalize binary files' '
 	git read-tree --reset -u HEAD &&
 
 	has_cr three &&
-	threediff=`git diff three` &&
+	threediff=$(git diff three) &&
 	test -z "$threediff"
 '