ext4: fix possible leak of s_journal_flag_rwsem in error path

ext4: fix possible leak of s_journal_flag_rwsem in error path

BugLink: https://bugs.launchpad.net/bugs/1836802
commit af18e35bfd01e6d65a5e3ef84ffe8b252d1628c5 upstream.

Fixes: c8585c6fcaf2 ("ext4: fix races between changing inode journal ...")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org # 4.7
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>