checkpatch: do not warn for multiline parenthesized returned value

While indeed we do not want to have

    return (a);

it is less clear that this applies to

    return (a &&
            b);

Some editors indent more nicely if you have parentheses, and some people's
eyes may appreciate that as well.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1561116534-21814-1-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

scripts/checkpatch.pl

@@ -2296,7 +2296,8 @@ sub process {
 			       $value =~ s/\([^\(\)]*\)/1/) {
 			}
 #print "value<$value>\n";
-			if ($value =~ /^\s*(?:$Ident|-?$Constant)\s*$/) {
+			if ($value =~ /^\s*(?:$Ident|-?$Constant)\s*$/ &&
+			    $line =~ /;$/) {
 				ERROR("return is not a function, parentheses are not required\n" . $herecurr);
 
 			} elsif ($spacing !~ /\s+/) {