jffs2: drop null test before destroy functions

Remove unneeded NULL test.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@ expression x; @@
-if (x != NULL)
  \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

fs/jffs2/malloc.c

@@ -97,24 +97,15 @@ int __init jffs2_create_slab_caches(void)
 
 void jffs2_destroy_slab_caches(void)
 {
-	if(full_dnode_slab)
 	kmem_cache_destroy(full_dnode_slab);
-	if(raw_dirent_slab)
 	kmem_cache_destroy(raw_dirent_slab);
-	if(raw_inode_slab)
 	kmem_cache_destroy(raw_inode_slab);
-	if(tmp_dnode_info_slab)
 	kmem_cache_destroy(tmp_dnode_info_slab);
-	if(raw_node_ref_slab)
 	kmem_cache_destroy(raw_node_ref_slab);
-	if(node_frag_slab)
 	kmem_cache_destroy(node_frag_slab);
-	if(inode_cache_slab)
 	kmem_cache_destroy(inode_cache_slab);
 #ifdef CONFIG_JFFS2_FS_XATTR
-	if (xattr_datum_cache)
 	kmem_cache_destroy(xattr_datum_cache);
-	if (xattr_ref_cache)
 	kmem_cache_destroy(xattr_ref_cache);
 #endif
 }