SUNRPC: call_connect_status should handle -EPROTO

The xprtrdma connect logic can return -EPROTO if the underlying
device or network path does not support RDMA. This can happen
after a device removal/insertion.

- When SOFTCONN is set, EPROTO is a permanent error.

- When SOFTCONN is not set, EPROTO is treated as a temporary error.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/clnt.c

@@ -2130,6 +2130,7 @@ call_connect_status(struct rpc_task *task)
 	case -ENETUNREACH:
 	case -EHOSTUNREACH:
 	case -EPIPE:
+	case -EPROTO:
 		xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
 					    task->tk_rqstp->rq_connect_cookie);
 		if (RPC_IS_SOFTCONN(task))