checkpatch: report missing spaces around trigraphs with --strict

Spaces around trigraphs are specified by CodingStyle but checkpatch is
currently silent about them because there are many current instances
without them.

Make missing spaces around trigraphs a --strict message.

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

@@ -2838,7 +2838,7 @@ sub process {
 				\+=|-=|\*=|\/=|%=|\^=|\|=|&=|
 				=>|->|<<|>>|<|>|=|!|~|
 				&&|\|\||,|\^|\+\+|--|&|\||\+|-|\*|\/|%|
-				\?|:
+				\?:|\?|:
 			}x;
 			my @elements = split(/($ops|;)/, $opline);
 
@@ -3061,15 +3061,13 @@ sub process {
 					    	$ok = 1;
 					}
 
-					# Ignore ?:
-					if (($opv eq ':O' && $ca =~ /\?$/) ||
-					    ($op eq '?' && $cc =~ /^:/)) {
-					    	$ok = 1;
-					}
-
+					# messages are ERROR, but ?: are CHK
 					if ($ok == 0) {
-						if (ERROR("SPACING",
-							  "spaces required around that '$op' $at\n" . $hereptr)) {
+						my $msg_type = \&ERROR;
+						$msg_type = \&CHK if (($op eq '?:' || $op eq '?' || $op eq ':') && $ctx =~ /VxV/);
+
+						if (&{$msg_type}("SPACING",
+								 "spaces required around that '$op' $at\n" . $hereptr)) {
 							$good = rtrim($fix_elements[$n]) . " " . trim($fix_elements[$n + 1]) . " ";
 							if (defined $fix_elements[$n + 2]) {
 								$fix_elements[$n + 2] =~ s/^\s+//;