btrfs: fix warning messages not printing interval at unpin_extent_range()

At unpin_extent_range() we print warning messages that are supposed to
print an interval in the form "[X, Y)", with the first element being an
inclusive start offset and the second element being the exclusive end
offset of a range. However we end up printing the range's length instead
of the range's exclusive end offset, so fix that to avoid having confusing
and non-sense messages in case we hit one of these unexpected scenarios.

Fixes: 00deaf04 ("btrfs: log messages at unpin_extent_range() during unexpected cases")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/extent_map.c

@@ -309,7 +309,7 @@ int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen)
 		btrfs_warn(fs_info,
 "no extent map found for inode %llu (root %lld) when unpinning extent range [%llu, %llu), generation %llu",
 			   btrfs_ino(inode), btrfs_root_id(inode->root),
-			   start, len, gen);
+			   start, start + len, gen);
 		ret = -ENOENT;
 		goto out;
 	}
@@ -318,7 +318,7 @@ int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen)
 		btrfs_warn(fs_info,
 "found extent map for inode %llu (root %lld) with unexpected start offset %llu when unpinning extent range [%llu, %llu), generation %llu",
 			   btrfs_ino(inode), btrfs_root_id(inode->root),
-			   em->start, start, len, gen);
+			   em->start, start, start + len, gen);
 		ret = -EUCLEAN;
 		goto out;
 	}