UBIFS: Fix dump messages in ubifs_dump_lprops

Function ubifs_read_one_lp will not set @lp and returns
an error when ubifs_read_one_lp failed. We should not
perform ubifs_dump_lprop in this case because @lp is not
initialized as we wanted.

Signed-off-by: hujianyang <hujianyang@huawei.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>