spi: rspi: Make qspi_set_send_trigger() return "unsigned int"

qspi_set_send_trigger() returns an unsigned value, so make it return
"unsigned int".
Update the loop variables qspi_trigger_transfer_out_int() to match the
above.

Signed-off-by: Geert Uytterhoeven <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/spi/spi-rspi.c

···
 	rspi_write8(rspi, data, reg);
 }
 
-static int qspi_set_send_trigger(struct rspi_data *rspi, unsigned int len)
+static unsigned int qspi_set_send_trigger(struct rspi_data *rspi,
+					  unsigned int len)
 {
 	unsigned int n;
 
···
 static int qspi_trigger_transfer_out_in(struct rspi_data *rspi, const u8 *tx,
 					u8 *rx, unsigned int len)
 {
-	int i, n, ret;
+	unsigned int i, n;
+	int ret;
 
 	while (len > 0) {
 		n = qspi_set_send_trigger(rspi, len);