hfi1: 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>
Cc: Mike Marciniszyn <infinipath@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/rdma/hfi1/user_sdma.c b/drivers/staging/rdma/hfi1/user_sdma.c
index 5552661..6620262 100644
--- a/drivers/staging/rdma/hfi1/user_sdma.c
+++ b/drivers/staging/rdma/hfi1/user_sdma.c
@@ -486,8 +486,7 @@
 			}
 			kfree(pq->reqs);
 		}
-		if (pq->txreq_cache)
-			kmem_cache_destroy(pq->txreq_cache);
+		kmem_cache_destroy(pq->txreq_cache);
 		kfree(pq);
 		fd->pq = NULL;
 	}