checkpatch: allow parentheses on return handle array values

When we allow return to have surrounding parentheses when containing
comparison operators we are not correctly handling the case where the
values contain array sufffixes.  Squash them.

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>