wait_for_completion_interruptible_timeout() may return negative value.
In this case, checking if (t > 0)  will return true if t is unsigned.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>
Cc: stable@kernel.org (3.0+)
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>