virtio-mem: silence a static checker warning

task #29077503
commit 1c3d69ab5348b661616992206357a3ebf19b1008 upstream
statement on the first iteration through the loop.  I suspect that this
can't happen in real life, but returning a zero literal is cleaner and
silence the static checker warning.

Fixes: 5f1f79bbc9e2 ("virtio-mem: Paravirtualized memory hotplug")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200610085911.GC5439@mwandaSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
(cherry picked from ccommit 1c3d69ab5348b661616992206357a3ebf19b1008)
Signed-off-by: NAlex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

drivers/virtio/virtio_mem.c

@@ -1192,7 +1192,7 @@ static int virtio_mem_mb_plug_any_sb(struct virtio_mem *vm, unsigned long mb_id,
 						VIRTIO_MEM_MB_STATE_OFFLINE);
 	}
 
-	return rc;
+	return 0;
 }
 
 /*