hp_accel: Silence an uninitialized variable warning

If acpi_evaluate_integer() fails then "lret" isn't initialized.  I've
tweaked the error handling to avoid this issue.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDarren Hart <dvhart@linux.intel.com>

drivers/platform/x86/hp_accel.c

@@ -127,8 +127,10 @@ static int lis3lv02d_acpi_read(struct lis3lv02d *lis3, int reg, u8 *ret)
 	arg0.integer.value = reg;
 
 	status = acpi_evaluate_integer(dev->handle, "ALRD", &args, &lret);
+	if (ACPI_FAILURE(status))
+		return -EINVAL;
 	*ret = lret;
-	return (status != AE_OK) ? -EINVAL : 0;
+	return 0;
 }
 
 /**