btrfs: tree-checker: fix misleading root drop_level error message

Fix tree-checker error message to report "invalid root drop_level"
instead of the misleading "invalid root level".

Fixes: 259ee77 ("btrfs: tree-checker: Add ROOT_ITEM check")
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: ZhengYuan Huang <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Author: Gality369

fs/btrfs/tree-checker.c

@@ -1284,7 +1284,7 @@ static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key,
 	}
 	if (unlikely(btrfs_root_drop_level(&ri) >= BTRFS_MAX_LEVEL)) {
 		generic_err(leaf, slot,
-			    "invalid root level, have %u expect [0, %u]",
+			    "invalid root drop_level, have %u expect [0, %u]",
 			    btrfs_root_drop_level(&ri), BTRFS_MAX_LEVEL - 1);
 		return -EUCLEAN;
 	}