i2c: sh_mobile: refactor rx isr

Remove the do_while loop which was just there to have an easy exit with
"break;" and replace it with if-else-blocks which should make the state
machine clearer.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-sh_mobile.c

@@ -373,25 +373,18 @@ static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
 	unsigned char data;
 	int real_pos;
 
-	do {
+	real_pos = pd->pos - 2;
+
 	if (pd->pos == -1) {
 		i2c_op(pd, OP_TX_FIRST);
-			break;
-		}
-
-		if (pd->pos == 0) {
+	} else if (pd->pos == 0) {
 		i2c_op(pd, OP_TX_TO_RX);
-			break;
-		}
-
-		real_pos = pd->pos - 2;
-
-		if (pd->pos == pd->msg->len) {
+	} else if (pd->pos == pd->msg->len) {
 		if (pd->stop_after_dma) {
 			/* Simulate PIO end condition after DMA transfer */
 			i2c_op(pd, OP_RX_STOP);
 			pd->pos++;
-				break;
+			goto done;
 		}
 
 		if (real_pos < 0)
@@ -404,8 +397,7 @@ static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
 
 	if (real_pos >= 0)
 		pd->msg->buf[real_pos] = data;
-	} while (0);
-
+ done:
 	pd->pos++;
 	return pd->pos == (pd->msg->len + 2);
 }