net/mlx5: Fix error code in mlx5_is_reset_now_capable()

The mlx5_is_reset_now_capable() function returns bool, not negative
error codes.  So if fast teardown is not supported it should return
false instead of -EOPNOTSUPP.

Fixes: 92501fa6 ("net/mlx5: Ack on sync_reset_request only if PF can do reset_now")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>