checkpatch: improve return negative errno check

Add a few conditions to the test to find
	return (ERRNO);

Make the output message a bit less cryptic too.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 file changed