ACPI / SBS: Enable battery manager when present

Commit 9faf6136ff46 (ACPI / SBS: Disable smart battery manager on
Apple) introduced a regression disabling the SBS battery manager.
The battery manager should be marked as present when
acpi_manager_get_info() returns 0.

Fixes: 9faf6136ff46 (ACPI / SBS: Disable smart battery manager on Apple)
Signed-off-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Cc: 3.18+ <stable@vger.kernel.org> # 3.18+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/sbs.c

@@ -684,7 +684,7 @@ static int acpi_sbs_add(struct acpi_device *device)
 	if (!sbs_manager_broken) {
 		result = acpi_manager_get_info(sbs);
 		if (!result) {
-			sbs->manager_present = 0;
+			sbs->manager_present = 1;
 			for (id = 0; id < MAX_SBS_BAT; ++id)
 				if ((sbs->batteries_supported & (1 << id)))
 					acpi_battery_add(sbs, id);