migration/rdma: Use error_report to suppress errno message

Since the prior calls are successful, in this case a errno doesn't
indicate a real error which would just make us confused.

before:
(qemu) migrate -d rdma:192.168.22.23:8888
source_resolve_host RDMA Device opened: kernel name rxe_eth0 uverbs device name uverbs2, infiniband_verbs class device path /sys/class/infiniband_verbs/uverbs2, infiniband class device path /sys/class/infiniband/rxe_eth0, transport: (2) Ethernet
rdma_get_cm_event != EVENT_ESTABLISHED after rdma_connect: No space left on device

Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Message-Id: <20210628071959.23455-1-lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

migration/rdma.c

@@ -1006,7 +1006,7 @@ static int qemu_rdma_resolve_host(RDMAContext *rdma, Error **errp)
     if (cm_event->event != RDMA_CM_EVENT_ADDR_RESOLVED) {
         ERROR(errp, "result not equal to event_addr_resolved %s",
                 rdma_event_str(cm_event->event));
-        perror("rdma_resolve_addr");
+        error_report("rdma_resolve_addr");
         rdma_ack_cm_event(cm_event);
         ret = -EINVAL;
         goto err_resolve_get_addr;
@@ -2544,7 +2544,7 @@ static int qemu_rdma_connect(RDMAContext *rdma, Error **errp, bool return_path)
     }
 
     if (cm_event->event != RDMA_CM_EVENT_ESTABLISHED) {
-        perror("rdma_get_cm_event != EVENT_ESTABLISHED after rdma_connect");
+        error_report("rdma_get_cm_event != EVENT_ESTABLISHED after rdma_connect");
         ERROR(errp, "connecting to destination!");
         rdma_ack_cm_event(cm_event);
         goto err_rdma_source_connect;