In dlm_init, if create dlm_lockname_cache failed in
dlm_init_master_caches, it will destroy dlm_lockres_cache which created
before twice.  And this will cause system die when loading modules.
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 
 void dlm_destroy_master_caches(void)
 {
-       if (dlm_lockname_cache)
+       if (dlm_lockname_cache) {
                kmem_cache_destroy(dlm_lockname_cache);
+               dlm_lockname_cache = NULL;
+       }
 
-       if (dlm_lockres_cache)
+       if (dlm_lockres_cache) {
                kmem_cache_destroy(dlm_lockres_cache);
+               dlm_lockres_cache = NULL;
+       }
 }
 
 static void dlm_lockres_release(struct kref *kref)