Several tests: cd inside subshell instead of around

Fixed all places where it was a straightforward change from cd'ing into a
directory and back via "cd .." to a cd inside a subshell.

Found these places with "git grep -w "cd \.\.".

Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t9114-git-svn-dcommit-merge.sh

@@ -37,11 +37,11 @@ EOF
 test_expect_success 'setup svn repository' '
 	svn_cmd co "$svnrepo" mysvnwork &&
 	mkdir -p mysvnwork/trunk &&
-	cd mysvnwork &&
+	(cd mysvnwork &&
 		big_text_block >> trunk/README &&
 		svn_cmd add trunk &&
-		svn_cmd ci -m "first commit" trunk &&
-		cd ..
+		svn_cmd ci -m "first commit" trunk
+		)
 	'
 
 test_expect_success 'setup git mirror and merge' '