migration/multifd: Add a wrapper for channels_created

We'll need to access multifd_send_state->channels_created from outside
multifd.c, so introduce a helper for that.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240229153017.2221-17-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>

migration/multifd.c

@@ -101,6 +101,11 @@ static bool multifd_use_packets(void)
     return !migrate_mapped_ram();
 }
 
+void multifd_send_channel_created(void)
+{
+    qemu_sem_post(&multifd_send_state->channels_created);
+}
+
 /* Multifd without compression */
 
 /**
@@ -1023,7 +1028,7 @@ static void multifd_new_send_channel_async(QIOTask *task, gpointer opaque)
      * Here we're not interested whether creation succeeded, only that
      * it happened at all.
      */
-    qemu_sem_post(&multifd_send_state->channels_created);
+    multifd_send_channel_created();
 
     if (ret) {
         return;

migration/multifd.h

@@ -17,6 +17,7 @@ typedef struct MultiFDRecvData MultiFDRecvData;
 
 bool multifd_send_setup(void);
 void multifd_send_shutdown(void);
+void multifd_send_channel_created(void);
 int multifd_recv_setup(Error **errp);
 void multifd_recv_cleanup(void);
 void multifd_recv_shutdown(void);