checkpatch: fix krealloc reuse test

The current krealloc test does not function correctly when the temporary
pointer return name contains the original pointer name.

Fix that by maximally matching the return pointer name and the original
pointer name and doing a separate comparison of the both names.

Link: http://lkml.kernel.org/r/e617ecb8c019a9c4c56540a1bec16c8aed43a4e4.camel@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Reported-by: NLars-Peter Clausen <lars@metafoo.de>
Cc: Manish Narani <manish.narani@xilinx.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

@@ -6167,7 +6167,8 @@ sub process {
 
 # check for krealloc arg reuse
 		if ($perl_version_ok &&
-		    $line =~ /\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*krealloc\s*\(\s*\1\s*,/) {
+		    $line =~ /\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*krealloc\s*\(\s*($Lval)\s*,/ &&
+		    $1 eq $3) {
 			WARN("KREALLOC_ARG_REUSE",
 			     "Reusing the krealloc arg is almost always a bug\n" . $herecurr);
 		}