staging: lustre: mgc: Use !x to check for kzalloc failure

!x is more normal for kzalloc failure in the kernel.

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

// <smpl>
@@
expression x;
statement S1, S2;
@@

x = kzalloc(...);
if (
- x == NULL
+ !x
 ) S1 else S2
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/mgc/mgc_request.c

@@ -1128,7 +1128,7 @@ static int mgc_apply_recover_logs(struct obd_device *mgc,
 	LASSERT(cfg->cfg_sb == cfg->cfg_instance);
 
 	inst = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
-	if (inst == NULL)
+	if (!inst)
 		return -ENOMEM;
 
 	if (!IS_SERVER(lsi)) {
@@ -1493,7 +1493,7 @@ static int mgc_process_cfg_log(struct obd_device *mgc,
 		lsi = s2lsi(cld->cld_cfg.cfg_sb);
 
 	env = kzalloc(sizeof(*env), GFP_NOFS);
-	if (env == NULL)
+	if (!env)
 		return -ENOMEM;
 
 	rc = lu_env_init(env, LCT_MG_THREAD);