staging: lustre: obdclass: Replace kmem_cache_alloc with kmem_cache_zalloc

Use kmem_cache_zalloc instead of manually setting kmem_cache_alloc
with flag GFP_ZERO since kmem_alloc_zalloc sets allocated memory
to zero.

The Coccinelle semantic patch used to make this change is as
follows:
// <smpl>
@@
expression e,f;
@@
- kmem_cache_alloc(e, f |__GFP_ZERO)
+ kmem_cache_zalloc(e, f)
// </smpl>
Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/obdclass/cl_lock.c

@@ -361,7 +361,7 @@ static struct cl_lock *cl_lock_alloc(const struct lu_env *env,
 	struct cl_lock	  *lock;
 	struct lu_object_header *head;
 
-	lock = kmem_cache_alloc(cl_lock_kmem, GFP_NOFS | __GFP_ZERO);
+	lock = kmem_cache_zalloc(cl_lock_kmem, GFP_NOFS);
 	if (lock) {
 		atomic_set(&lock->cll_ref, 1);
 		lock->cll_descr = *descr;

drivers/staging/lustre/lustre/obdclass/cl_object.c

@@ -659,7 +659,7 @@ static struct lu_env *cl_env_new(__u32 ctx_tags, __u32 ses_tags, void *debug)
 	struct lu_env *env;
 	struct cl_env *cle;
 
-	cle = kmem_cache_alloc(cl_env_kmem, GFP_NOFS | __GFP_ZERO);
+	cle = kmem_cache_zalloc(cl_env_kmem, GFP_NOFS);
 	if (cle) {
 		int rc;
 

drivers/staging/lustre/lustre/obdclass/genops.c

@@ -69,7 +69,7 @@ static struct obd_device *obd_device_alloc(void)
 {
 	struct obd_device *obd;
 
-	obd = kmem_cache_alloc(obd_device_cachep, GFP_NOFS | __GFP_ZERO);
+	obd = kmem_cache_zalloc(obd_device_cachep, GFP_NOFS);
 	if (obd)
 		obd->obd_magic = OBD_DEVICE_MAGIC;
 	return obd;