staging: et131x: Add spinlock definition comments

Checkpatch --strict advises that spinlocks should be described when
defined, seems a good idea so this change does that.
Signed-off-by: Mark Einon <mark.einon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/et131x/et131x.c

@@ -474,10 +474,9 @@ struct et131x_adapter {
 	bool has_eeprom;
 	u8 eeprom_data[2];
 
-	/* Spinlocks */
-	spinlock_t tcb_send_qlock;
-	spinlock_t tcb_ready_qlock;
-	spinlock_t rcv_lock;
+	spinlock_t tcb_send_qlock; /* protects the tx_ring send tcb list */
+	spinlock_t tcb_ready_qlock; /* protects the tx_ring ready tcb list */
+	spinlock_t rcv_lock; /* protects the rx_ring receive list */
 
 	/* Packet Filter and look ahead size */
 	u32 packet_filter;