xprtrdma: Rename "xprt" and "rdma_connect" fields in struct rpcrdma_xprt

Clean up: Use consistent field names in struct rpcrdma_xprt.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>