checkpatch: fix bug in regular expression

Recent version of perl seem to report incorrect stuff in regular expression
and this seems to be fixed in the kernel reference file, so this patch
brings the fix to our (older) version so we won't get that spurious message
when running the script.

Signed-off-by: Christophe CURIS <christophe.curis@free.fr>

checkpatch.pl

@@ -1911,7 +1911,7 @@ sub process {
 				"please, no space before tabs\n" . $herevet) &&
 			    $fix) {
 				while ($fixed[$linenr - 1] =~
-					   s/(^\+.*) {8,8}+\t/$1\t\t/) {}
+					   s/(^\+.*) {8,8}\t/$1\t\t/) {}
 				while ($fixed[$linenr - 1] =~
 					   s/(^\+.*) +\t/$1\t/) {}
 			}