macosx/simple prefs: drop explicit singleton

modules/gui/macosx/simple_prefs.h

@@ -27,8 +27,6 @@
 
 @interface VLCSimplePrefs : NSObject
 
-+ (VLCSimplePrefs *)sharedInstance;
-
 @property (readwrite, weak) IBOutlet NSPopUpButton *audio_dolbyPopup;
 @property (readwrite, weak) IBOutlet NSTextField *audio_dolbyLabel;
 @property (readwrite, weak) IBOutlet NSBox *audio_effectsBox;

modules/gui/macosx/simple_prefs.m

@@ -204,18 +204,6 @@ static NSString* VLCHotkeysSettingToolbarIdentifier = @"Hotkeys Settings Item Id
 
 #pragma mark Initialisation
 
-+ (VLCSimplePrefs *)sharedInstance
-{
-    static VLCSimplePrefs *sharedInstance = nil;
-    static dispatch_once_t pred;
-
-    dispatch_once(&pred, ^{
-        sharedInstance = [VLCSimplePrefs new];
-    });
-
-    return sharedInstance;
-}
-
 - (id)init
 {
     self = [super init];