checkpatch: complex macros checks miss square brackets

We are missing 'simple' values which include square brackets.  Refactor to
ensure we handle nesting correctly and detect these simple forms.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

@@ -2142,9 +2142,10 @@ sub process {
 			$dstat =~ s/\s*$//s;
 
 			# Flatten any parentheses and braces
-			while ($dstat =~ s/\([^\(\)]*\)/1/) {
-			}
-			while ($dstat =~ s/\{[^\{\}]*\}/1/) {
+			while ($dstat =~ s/\([^\(\)]*\)/1/ ||
+			       $dstat =~ s/\{[^\{\}]*\}/1/ ||
+			       $dstat =~ s/\[[^\{\}]*\]/1/)
+			{
 			}
 
 			my $exceptions = qr{