ios: Don't show the 'Stop Bluetooth' button unless BTStack is running.

ios/RetroArch/BTStack/WiiMoteHelper.h

@@ -35,6 +35,7 @@
 
 @interface WiiMoteHelper : NSObject<BTDiscoveryDelegate, BTstackManagerDelegate, BTstackManagerListener>
 + (WiiMoteHelper*)get;
++ (BOOL)isBluetoothRunning;
 + (void)stopBluetooth;
 - (void)showDiscovery;
 @end

ios/RetroArch/BTStack/WiiMoteHelper.m

@@ -61,6 +61,11 @@ static bool btOK;
    return instance;
 }
 
++ (BOOL)isBluetoothRunning
+{
+   return btOK;
+}
+
 + (void)stopBluetooth
 {
    instance = nil;

ios/RetroArch/RetroArch_iOS.m

@@ -63,12 +63,12 @@
 - (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
 {
 #ifdef WIIMOTE
-   UIBarButtonItem* bbi = [[UIBarButtonItem alloc]
-                          initWithTitle:@"Stop Bluetooth"
-                          style:UIBarButtonItemStyleBordered
-                          target:[RetroArch_iOS get]
-                          action:@selector(stopBluetooth)];
-   navigationController.topViewController.navigationItem.rightBarButtonItem = bbi;
+   navigationController.topViewController.navigationItem.rightBarButtonItem = (![WiiMoteHelper isBluetoothRunning]) ? nil :
+                           [[UIBarButtonItem alloc]
+                           initWithTitle:@"Stop Bluetooth"
+                           style:UIBarButtonItemStyleBordered
+                           target:[RetroArch_iOS get]
+                           action:@selector(stopBluetooth)];
 #endif
 }
 
@@ -374,6 +374,7 @@
 {
 #ifdef WIIMOTE
    [WiiMoteHelper stopBluetooth];
+   [_navigator.topViewController.navigationItem setRightBarButtonItem:nil animated:YES];
 #endif
 }