staging: lustre: obdclass: race lustre_profile_list

Running multiple mounts at the same time results in
lustre_profile_list corruption when adding a new profile.

This patch adds a new spin_lock to protect the list and
avoid the bug

Signed-off-by: Hiroya Nozaki <nozaki.hiroya@jp.fujitsu.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6600
Reviewed-on: http://review.whamcloud.com/14896


Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.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>