staging: lustre: lclient: 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/lclient/lcommon_cl.c

@@ -203,7 +203,7 @@ struct lu_device *ccc_device_alloc(const struct lu_env *env,
 	int rc;
 
 	vdv = kzalloc(sizeof(*vdv), GFP_NOFS);
-	if (vdv == NULL)
+	if (!vdv)
 		return ERR_PTR(-ENOMEM);
 
 	lud = &vdv->cdv_cl.cd_lu_dev;