migration: close socket QEMUFile from socket_close

The common suffix now is process_incoming_migration+qemu_fclose.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

migration-unix.c

@@ -103,6 +103,8 @@ static void unix_accept_incoming_migration(void *opaque)
 
     process_incoming_migration(f);
     qemu_fclose(f);
+    return;
+
 out:
     close(c);
 }