RDMA/ocrdma: fix double free on pd

RDMA/ocrdma: fix double free on pd

A reorganisation of the PD allocation and deallocation in commit
9ba1377daa ("RDMA/ocrdma: Move PD resource management to driver.")
introduced a double free on pd, as detected by static analysis by
smatch:

drivers/infiniband/hw/ocrdma/ocrdma_verbs.c:682 ocrdma_alloc_pd()
  error: double free of 'pd'^

The original call to ocrdma_mbx_dealloc_pd() (which does not kfree
pd) was replaced with a call to _ocrdma_dealloc_pd() (which does
kfree pd).  The kfree following this call causes the double free,
so just remove it to fix the problem.

Fixes: 9ba1377daa ("RDMA/ocrdma: Move PD resource management to driver.")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-By: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>