rdma: Fix incorrect description in comments

Since we have supported memory hotplug, VM's ram include pc.ram
and hotplug-memory.

Fix the confused description for rdma migration: pc.ram -> VM's ram

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff --git a/migration-rdma.c b/migration-rdma.c
index d99812c..b32dbdf 100644
--- a/migration-rdma.c
+++ b/migration-rdma.c
@@ -2523,7 +2523,7 @@
 /*
  * QEMUFile interface to the control channel.
  * SEND messages for control only.
- * pc.ram is handled with regular RDMA messages.
+ * VM's ram is handled with regular RDMA messages.
  */
 static int qemu_rdma_put_buffer(void *opaque, const uint8_t *buf,
                                 int64_t pos, int size)
@@ -2539,7 +2539,7 @@
 
     /*
      * Push out any writes that
-     * we're queued up for pc.ram.
+     * we're queued up for VM's ram.
      */
     ret = qemu_rdma_write_flush(f, rdma);
     if (ret < 0) {