RDMA: Properly propagate the number of CQEs as unsigned int

RDMA: Properly propagate the number of CQEs as unsigned int

Instead of checking whether the number of CQEs is negative or zero, fix the
.resize_user_cq() declaration to use unsigned int. This better reflects the
expected value range. The sanity check is then handled correctly in ib_uvbers.

Link: https://patch.msgid.link/20260319-resize_cq-cqe-v1-1-b78c6efc1def@nvidia.com
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>