bcachefs: Make btree root read errors recoverable

The entire btree will be lost, but that is better than the entire
filesystem not being recoverable.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/recovery.c

@@ -374,13 +374,12 @@ static int read_btree_roots(struct bch_fs *c)
 
 		ret = bch2_btree_root_read(c, i, &r->key, r->level);
 		if (ret) {
-			__fsck_err(c,
-				   btree_id_is_alloc(i)
-				   ? FSCK_CAN_IGNORE : 0,
-				   "error reading btree root %s",
-				   bch2_btree_ids[i]);
+			fsck_err(c,
+				 "error reading btree root %s",
+				 bch2_btree_ids[i]);
 			if (btree_id_is_alloc(i))
 				c->sb.compat &= ~(1ULL << BCH_COMPAT_alloc_info);
+			ret = 0;
 		}
 	}