migration: Fix warnings caused by missing 'static' attribute

Warnings from the Sparse static analysis tool:

migration-rdma.c:151:12: warning:
 symbol 'wrid_desc' was not declared. Should it be static?
migration-rdma.c:190:12: warning:
 symbol 'control_desc' was not declared. Should it be static?
migration-rdma.c:3301:19: warning:
 symbol 'rdma_read_ops' was not declared. Should it be static?
migration-rdma.c:3308:19: warning:
 symbol 'rdma_write_ops' was not declared. Should it be static?

Cc: Juan Quintela <quintela@redhat.com>
Cc: Amit Shah <amit.shah@redhat.com>
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

migration/rdma.c

@@ -121,7 +121,7 @@ enum {
     RDMA_WRID_RECV_CONTROL = 4000,
 };
 
-const char *wrid_desc[] = {
+static const char *wrid_desc[] = {
     [RDMA_WRID_NONE] = "NONE",
     [RDMA_WRID_RDMA_WRITE] = "WRITE RDMA",
     [RDMA_WRID_SEND_CONTROL] = "CONTROL SEND",
@@ -160,7 +160,7 @@ enum {
     RDMA_CONTROL_UNREGISTER_FINISHED, /* unpinning finished */
 };
 
-const char *control_desc[] = {
+static const char *control_desc[] = {
     [RDMA_CONTROL_NONE] = "NONE",
     [RDMA_CONTROL_ERROR] = "ERROR",
     [RDMA_CONTROL_READY] = "READY",
@@ -3250,14 +3250,14 @@ static int qemu_rdma_get_fd(void *opaque)
     return rdma->comp_channel->fd;
 }
 
-const QEMUFileOps rdma_read_ops = {
+static const QEMUFileOps rdma_read_ops = {
     .get_buffer    = qemu_rdma_get_buffer,
     .get_fd        = qemu_rdma_get_fd,
     .close         = qemu_rdma_close,
     .hook_ram_load = qemu_rdma_registration_handle,
 };
 
-const QEMUFileOps rdma_write_ops = {
+static const QEMUFileOps rdma_write_ops = {
     .put_buffer         = qemu_rdma_put_buffer,
     .close              = qemu_rdma_close,
     .before_ram_iterate = qemu_rdma_registration_start,