zoul: fix return type of grove_gyro_read_reg
GROVE_GYRO_ERROR is defined as -1, so use a signed
type that can represent the value.
@@ -66,7 +66,7 @@ grove_gyro_values_t gyro_values;
/*---------------------------------------------------------------------------*/
void (*grove_gyro_int_callback)(uint8_t value);
/*---------------------------------------------------------------------------*/
-static uint16_t
+static int
grove_gyro_read_reg(uint8_t reg, uint8_t *buf, uint8_t num)
{
if((buf == NULL) || (num <= 0)) {
