checkpatch: handle C99 comments correctly (performance issue)

This fixes the sanitation process in checkpatch.pl so that it blocks out
the text after a C99 style comment the same way it does with block style
comments.  This prevents the text from getting processed as regular code.
Signed-off-by: Daniel Walker <dwalker@fifo99.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

@@ -356,6 +356,13 @@ sub sanitise_line {
 			$off++;
 			next;
 		}
+		if ($sanitise_quote eq '' && substr($line, $off, 2) eq '//') {
+			$sanitise_quote = '//';
+
+			substr($res, $off, 2, $sanitise_quote);
+			$off++;
+			next;
+		}
 
 		# A \ in a string means ignore the next character.
 		if (($sanitise_quote eq "'" || $sanitise_quote eq '"') &&
@@ -379,6 +386,8 @@ sub sanitise_line {
 		#print "c<$c> SQ<$sanitise_quote>\n";
 		if ($off != 0 && $sanitise_quote eq '*/' && $c ne "\t") {
 			substr($res, $off, 1, $;);
+		} elsif ($off != 0 && $sanitise_quote eq '//' && $c ne "\t") {
+			substr($res, $off, 1, $;);
 		} elsif ($off != 0 && $sanitise_quote && $c ne "\t") {
 			substr($res, $off, 1, 'X');
 		} else {
@@ -386,6 +395,10 @@ sub sanitise_line {
 		}
 	}
 
+	if ($sanitise_quote eq '//') {
+		$sanitise_quote = '';
+	}
+
 	# The pathname on a #include may be surrounded by '<' and '>'.
 	if ($res =~ /^.\s*\#\s*include\s+\<(.*)\>/) {
 		my $clean = 'X' x length($1);