i2c: aspeed: use proper annotation for "fall through"

Use a better annotation, so GCC won't complain anymore:

drivers/i2c/busses/i2c-aspeed.c:458:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-aspeed.c

@@ -456,7 +456,7 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
 			goto error_and_stop;
 		}
 		irq_handled |= ASPEED_I2CD_INTR_TX_ACK;
-		/* fallthrough intended */
+		/* fall through */
 	case ASPEED_I2C_MASTER_TX_FIRST:
 		if (bus->buf_index < msg->len) {
 			bus->master_state = ASPEED_I2C_MASTER_TX;
@@ -472,7 +472,7 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
 		/* RX may not have completed yet (only address cycle) */
 		if (!(irq_status & ASPEED_I2CD_INTR_RX_DONE))
 			goto out_no_complete;
-		/* fallthrough intended */
+		/* fall through */
 	case ASPEED_I2C_MASTER_RX:
 		if (unlikely(!(irq_status & ASPEED_I2CD_INTR_RX_DONE))) {
 			dev_err(bus->dev, "master failed to RX\n");