dlm: NULL check before kmem_cache_destroy is not needed

BugLink: https://bugs.launchpad.net/bugs/1858489

[ Upstream commit f31a8969 ]

kmem_cache_destroy(NULL) is safe, so removes NULL check before
freeing the mem. This patch also fix ifnullfree.cocci warnings.
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

fs/dlm/memory.c

@@ -38,10 +38,8 @@ int __init dlm_memory_init(void)
 
 void dlm_memory_exit(void)
 {
-	if (lkb_cache)
-		kmem_cache_destroy(lkb_cache);
-	if (rsb_cache)
-		kmem_cache_destroy(rsb_cache);
+	kmem_cache_destroy(lkb_cache);
+	kmem_cache_destroy(rsb_cache);
 }
 
 char *dlm_allocate_lvb(struct dlm_ls *ls)
@@ -86,8 +84,7 @@ void dlm_free_lkb(struct dlm_lkb *lkb)
 		struct dlm_user_args *ua;
 		ua = lkb->lkb_ua;
 		if (ua) {
-			if (ua->lksb.sb_lvbptr)
-				kfree(ua->lksb.sb_lvbptr);
+			kfree(ua->lksb.sb_lvbptr);
 			kfree(ua);
 		}
 	}