btrfs-progs: fix find_mount_root() to handle duplicated mount point correctly

Original find_mount_root() will use the first mount point match and
return it.
It was OK until the following commit, which will also check the fstype:
de22c28ef31d9721606ba059 btrfs-progs: Check fstype in find_mount_root()

With fstype check, we should check the last match, not only the first
one.
Or the following mount will not pass the find_mount_root():
/dev/sdc on /mnt/test type ext4 (rw,relatime,data=ordered)
/dev/sdb on /mnt/test type btrfs (rw,relatime,space_cache)

This patch will use the last match to do the fstype check.

Reported-by: Remco Hosman <remco@yerf-it.nl>
Signed-off-by: Remco Hosman <remco@yerf-it.nl>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
btrfs-progs: remove btrfs_release_path before btrfs_free_path

The btrfs_free_path calls btrfs_release_path internally.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
btrfs-progs: remove wrong set_argv0 for restore

Before this patch, you could see the following after exec restore
	# :too few arguments

The tool name "btrfs restore" is missing.

The @set_argv0() function is introduced by:
	commit a184abc70f7b1468e6036ab576f1587ee0574668
	btrfs-progs: move the check_argc_* functions into utils.c
	...
	Also add a new function "set_argv0" to set the correct tool name:
        *btrfs-image*: too few arguments

But @set_argv0() only applies to the independent tools with
the name pattern btrfs-***.
Since restore is now is subcommand under "btrfs",
there is no need to use @set_argv0() before check_argc_* to
repair the prompt tool name before "too few arguments".

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
btrfs-progs: doc: fix invalid reference to setattr(8)

man 8 btrfs-property refers to `setattr(8)` which does not actually exist.
It should refer to `chattr (1)` instead.

Signed-off-by: Naohiro Aota <naota@elisp.net>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>