post-cocci: adjust comments for recent repo_* migration

In preceding commits we changed many calls to macros that were
providing a "the_repository" argument to invoke corresponding repo_*()
function instead. Let's follow-up and adjust references to those in
comments, which coccinelle didn't (and inherently can't) catch.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff.h

@@ -614,7 +614,7 @@ void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc);
 #define DIFF_STATUS_FILTER_BROKEN	'B'
 
 /*
- * This is different from find_unique_abbrev() in that
+ * This is different from repo_find_unique_abbrev() in that
  * it stuffs the result with dots for alignment.
  */
 const char *diff_aligned_abbrev(const struct object_id *sha1, int);