checkpatch: use the correct indentation for which()

I copied the which subroutine from get_maintainer.pl.

Unfortunately, get_maintainer uses a 4 space indentation so use the
proper tab indentation instead.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

@@ -710,15 +710,15 @@ sub format_email {
 }
 
 sub which {
-    my ($bin) = @_;
+	my ($bin) = @_;
 
-    foreach my $path (split(/:/, $ENV{PATH})) {
-	if (-e "$path/$bin") {
-	    return "$path/$bin";
+	foreach my $path (split(/:/, $ENV{PATH})) {
+		if (-e "$path/$bin") {
+			return "$path/$bin";
+		}
 	}
-    }
 
-    return "";
+	return "";
 }
 
 sub which_conf {