UBIFS: fix incorrect unlocking handling

When ubifs_init_security() fails, 'ui_mutex' is incorrectly
unlocked and incorrectly restores 'i_size'. Fix this.

Change-Id: I955737002aa4e8e544b4d8a67f7f8cd31e28acb1
Signed-off-by: Taesoo Kim <tsgatesv@gmail.com>
Fixes: d7f0b70d30ff ("UBIFS: Add security.* XATTR support for the UBIFS")
Reviewed-by: Ben Shelton <ben.shelton@ni.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Git-commit: 9401a795c6478953e10226471ba5990db5000e05
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Nikhilesh Reddy <reddyn@codeaurora.org>