fujitu-laptop: fix tests of acpi_evaluate_integer() return value

Fix tests on return value from acpi_evaluate_integer().  Based on a patch by
Roel Kluin <roel.kluin@gmail.com> and incorporating suggestions from Len
Brown <lenb@kernel.org>.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/platform/x86/fujitsu-laptop.c

@@ -376,8 +376,8 @@ static int get_lcd_level(void)
 
 	status =
 	    acpi_evaluate_integer(fujitsu->acpi_handle, "GBLL", NULL, &state);
-	if (status < 0)
-		return status;
+	if (ACPI_FAILURE(status))
+		return 0;
 
 	fujitsu->brightness_level = state & 0x0fffffff;
 
@@ -398,8 +398,8 @@ static int get_max_brightness(void)
 
 	status =
 	    acpi_evaluate_integer(fujitsu->acpi_handle, "RBLL", NULL, &state);
-	if (status < 0)
-		return status;
+	if (ACPI_FAILURE(status))
+		return -1;
 
 	fujitsu->max_brightness = state;