btrfs-progs: btrfstune: fix multiple options error

when we use multiple options, error return status will be override by the
last option status.

example: btrfstune -S 1 -r /dev/loop0

when -S option fails and -r option succeeds, return value is 0, rather than
1, where 1 is the right return status.

Reported-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
Signed-off-by: Fan Chengniang <fancn.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
1 file changed