Input: himax_hx83112b - fix incorrect size when reading product ID

We need to read a u32 value (4 bytes), not size of a pointer to that
value.

Also, himax_read_mcu() wrapper is an overkill, remove it and use
himax_bus_read() directly.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202408200301.Ujpj7Vov-lkp@intel.com/
Fixes: 0944829d ("Input: himax_hx83112b - implement MCU register reading")
Tested-by: Felix Kaechele <felix@kaechele.ca>
Link: https://lore.kernel.org/r/ZsPdmtfC54R7JVxR@google.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/himax_hx83112b.c

@@ -130,17 +130,6 @@ static int himax_bus_read(struct himax_ts_data *ts, u32 address, void *dst,
 	return 0;
 }
 
-static int himax_read_mcu(struct himax_ts_data *ts, u32 address, u32 *dst)
-{
-	int error;
-
-	error = himax_bus_read(ts, address, dst, sizeof(dst));
-	if (error)
-		return error;
-
-	return 0;
-}
-
 static void himax_reset(struct himax_ts_data *ts)
 {
 	gpiod_set_value_cansleep(ts->gpiod_rst, 1);
@@ -160,7 +149,8 @@ static int himax_read_product_id(struct himax_ts_data *ts, u32 *product_id)
 {
 	int error;
 
-	error = himax_read_mcu(ts, HIMAX_REG_ADDR_ICID, product_id);
+	error = himax_bus_read(ts, HIMAX_REG_ADDR_ICID, product_id,
+			       sizeof(*product_id));
 	if (error)
 		return error;