RDMA/irdma: Use s/g array in post send only when its valid

RDMA/irdma: Use s/g array in post send only when its valid

Send with invalidate verb call can pass in an
uninitialized s/g array with 0 sge's which is
filled into irdma WQE and causes a HW asynchronous
event.

Fix this by using the s/g array in irdma post send
only when its valid.

Fixes: 131c44e ("RDMA/irdma: Add user/kernel shared libraries")
Signed-off-by: Sindhu-Devale <sindhu.devale@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Link: https://lore.kernel.org/r/20220906223244.1119-5-shiraz.saleem@intel.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>