At the end of the delay loop timeout will always be zero
and hence the check for !timeout will always be true. Remove
the redundant check and the redundant return 0 at the end of
the function.

Fixes CoverityScan CID#1357168 ("Logically dead code")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>