buffered_file: unfold migrate_fd_put_buffer

We only used it once, just remove the callback indirection

Signed-off-by: Juan Quintela <quintela@redhat.com>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/migration.c b/migration.c
index 330c16a..f6ee7cd 100644
--- a/migration.c
+++ b/migration.c
@@ -295,10 +295,9 @@
     }
 }
 
-static ssize_t migrate_fd_put_buffer(void *opaque, const void *data,
-                                     size_t size)
+ssize_t migrate_fd_put_buffer(MigrationState *s, const void *data,
+                              size_t size)
 {
-    MigrationState *s = opaque;
     ssize_t ret;
 
     if (s->state != MIG_STATE_ACTIVE) {
@@ -436,7 +435,6 @@
     s->state = MIG_STATE_ACTIVE;
     s->file = qemu_fopen_ops_buffered(s,
                                       s->bandwidth_limit,
-                                      migrate_fd_put_buffer,
                                       migrate_fd_put_ready,
                                       migrate_fd_wait_for_unfreeze,
                                       migrate_fd_close);