xprtrdma: Remove temp allocation of rpcrdma_rep objects

The original code was designed so that most calls to
rpcrdma_rep_create() would occur on the NUMA node that the device
preferred. There are a few cases where that's not possible, so
those reps are marked as temporary.

However, we have the device (and its preferred node) already in
rpcrdma_rep_create(), so let's use that to guarantee the memory
is allocated from the correct node.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>