nfsd: drop null test before destroy functions

Author: Julia Lawall <Julia.Lawall@lip6.fr>

Remove unneeded NULL test.

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

// 
@@ expression x; @@
-if (x != NULL) {
  \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
  x = NULL;
-}
// 

Signed-off-by: Julia Lawall 
Signed-off-by: J. Bruce Fields 
---
 fs/nfsd/nfscache.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)
 
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 46ec934..116940c 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -217,10 +217,8 @@ void nfsd_reply_cache_shutdown(void)
 	drc_hashtbl = NULL;
 	drc_hashsize = 0;
 
-	if (drc_slab) {
-		kmem_cache_destroy(drc_slab);
-		drc_slab = NULL;
-	}
+	kmem_cache_destroy(drc_slab);
+	drc_slab = NULL;
 }
 
 /*