checkpatch: test SYMBOLIC_PERMS multiple times per line

There are occasions where symbolic perms are used in a ternary like

		return (channel == 0) ? S_IRUGO | S_IWUSR : S_IRUGO;

The current test will find the first use "S_IRUGO | S_IWUSR" but not the
second use "S_IRUGO" on the same line.

Improve the test to look for all instances on a line.

Link: http://lkml.kernel.org/r/1522127944.12357.49.camel@perches.com
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

@@ -6429,7 +6429,7 @@ sub process {
 		}
 
 # check for uses of S_<PERMS> that could be octal for readability
-		if ($line =~ /\b($multi_mode_perms_string_search)\b/) {
+		while ($line =~ m{\b($multi_mode_perms_string_search)\b}g) {
 			my $oval = $1;
 			my $octal = perms_to_octal($oval);
 			if (WARN("SYMBOLIC_PERMS",