LU-6524 llog: Incorrect use of ERR_PTR

LU-6524 llog: Incorrect use of ERR_PTR

This issue is raised by smatch as below description
llog_osd_destroy incorrectly tried to use ERR_PTR pointer
Resolution is changed rc value to ENOENT

Incorporated code review comments.
Removed ENOENT of earlier commit and updated ot path.

Signed-off-by: Ulka Vaze <ulka.vaze@yahoo.in>
Change-Id: I010c21763ac7fc3664214eda93ea18e1c2d35de6
Signed-off-by: Ulka Vaze <ulka.vaze@yahoo.in>
Reviewed-on: http://review.whamcloud.com/14876
Tested-by: Jenkins
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>