bcachefs: Kill incorrect assertion

In the bch2_fs_alloc() error path we call bch2_fs_free() without setting
BCH_FS_STOPPING - this is fine.

Signed-off-by: Kent Overstreet <[e-mail]>

fs/bcachefs/super.c

···
 {
 	unsigned i;
 
-	BUG_ON(!test_bit(BCH_FS_STOPPING, &c->flags));
-
 	mutex_lock(&bch_fs_list_lock);
 	list_del(&c->list);
 	mutex_unlock(&bch_fs_list_lock);