scripts/checkpatch.pl: avoid false warning missing break

void foo(int a)
	switch (a) {
	case 'h':
		fun1();
		exit(1);
	default:
}

creates a warning "Possible switch case/default not preceded by break or
fallthrough comment".

exit( should be treated like return.

Link: http://lkml.kernel.org/r/20170910154618.25819-1-xypron.glpk@gmx.deSigned-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-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

@@ -6109,7 +6109,7 @@ sub process {
 				next if ($fline =~ /^.[\s$;]*$/);
 				$has_statement = 1;
 				$count++;
-				$has_break = 1 if ($fline =~ /\bswitch\b|\b(?:break\s*;[\s$;]*$|return\b|goto\b|continue\b)/);
+				$has_break = 1 if ($fline =~ /\bswitch\b|\b(?:break\s*;[\s$;]*$|exit\s*\(\b|return\b|goto\b|continue\b)/);
 			}
 			if (!$has_break && $has_statement) {
 				WARN("MISSING_BREAK",