acer-wmi: fix rfkill conversion

Fix another polarity error introduced by the rfkill rewrite,
this time in acer_rfkill_set().
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/platform/x86/acer-wmi.c

@@ -973,7 +973,7 @@ static int acer_rfkill_set(void *data, bool blocked)
 {
 	acpi_status status;
 	u32 cap = (unsigned long)data;
-	status = set_u32(!!blocked, cap);
+	status = set_u32(!blocked, cap);
 	if (ACPI_FAILURE(status))
 		return -ENODEV;
 	return 0;