staging: lustre: mgc: IR log failure should not stop mount

staging: lustre: mgc: IR log failure should not stop mount

If clients or other targets can not get IR config lock
or lock, the mount should continue, instead of failing.
Because timeout mechanism will handle the recovery anyway.

Signed-off-by: wang di <di.wang@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6906
Reviewed-on: http://review.whamcloud.com/15728
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>