staging: ozwpan: Remove redundant null check before kfree in ozhcd.c

kfree on NULL pointer is a no-op.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Rupesh Gujare <rgujare@ozmodevices.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ozwpan/ozhcd.c

@@ -278,8 +278,7 @@ static void oz_free_urb_link(struct oz_urb_link *urbl)
 			g_link_pool_size++;
 		}
 		spin_unlock_irqrestore(&g_link_lock, irq_state);
-		if (urbl)
-			kfree(urbl);
+		kfree(urbl);
 	}
 }
 /*------------------------------------------------------------------------------