rdma: Fix statistics bind/unbing argument handling

rdma: Fix statistics bind/unbing argument handling

The dump isn't supported for the statistics bind/unbind commands
because they operate on specific QP counters. This is different
from query commands that can operate on many objects at the same
time.

Let's check the user input and ensure that arguments are valid.

Fixes: a6d0773ebecc ("rdma: Add stat manual mode support")
Signed-off-by: Ido Kalir <idok@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>