staging: lustre: lustre: mdc: lproc_mdc.c: Fix for potential NULL pointer dereference

In mdc_kuc_write(), OBD_ALLOC(lh, len) may leave 'lh' to NULL as kmalloc
may fail to allocate memory. This fix adds a check to avoid, dereferencing
a NULL pointer.
Signed-off-by: Kumar Amit Mehta <gmate.amit@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/mdc/lproc_mdc.c

@@ -106,6 +106,8 @@ static ssize_t mdc_kuc_write(struct file *file,
 		/* for mockup below */ 2 * cfs_size_round(sizeof(*hai));
 
 	OBD_ALLOC(lh, len);
+	if (!lh)
+		return -ENOMEM;
 
 	lh->kuc_magic = KUC_MAGIC;
 	lh->kuc_transport = KUC_TRANSPORT_HSM;