i2c: synquacer: fix fall-through annotation

Replace "fallthru" with a proper "fall through" annotation.

This fix is part of the ongoing efforts to enabling
-Wimplicit-fallthrough
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-synquacer.c

@@ -404,7 +404,7 @@ static irqreturn_t synquacer_i2c_isr(int irq, void *dev_id)
 		if (i2c->state == STATE_READ)
 			goto prepare_read;
 
-		/* fallthru */
+		/* fall through */
 
 	case STATE_WRITE:
 		if (bsr & SYNQUACER_I2C_BSR_LRB) {