RDMA/qib: Remove not-used variable n

The variable n being incremented but it is never referenced,
it is redundant and can be removed.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20221021172611.26763-1-colin.i.king@gmail.com


Signed-off-by: Leon Romanovsky <leon@kernel.org>