linux-phytec-ti

nvme: use UINT_MAX for max discard sectors

It's more elegant to use UINT_MAX to represent the max value of
type unsigned int. So replace the actual value by using this define.

Signed-off-by: Minfei Huang <mnghuan@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>