staging: lustre: ldlm: ldlm_lock: remove unneeded null test before free

Kfree can cope with a null argument, so drop null tests.

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

// <smpl>
@@ expression ptr; @@

- if (ptr != NULL)
  kfree(ptr);
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/ldlm/ldlm_lock.c

@@ -208,7 +208,6 @@ void ldlm_lock_put(struct ldlm_lock *lock)
 			lock->l_export = NULL;
 		}
 
-		if (lock->l_lvb_data != NULL)
 		kfree(lock->l_lvb_data);
 
 		ldlm_interval_free(ldlm_interval_detach(lock));