Minor Cocoa bug fixes

Cocoa/AppDelegate.m

@@ -327,6 +327,7 @@ static uint32_t color_to_int(NSColor *color)
                 self.updateProgressButton.enabled = true;
                 [self.updateProgressSpinner stopAnimation:nil];
             });
+            return;
         }
         
         unzipTask = [[NSTask alloc] init];

Cocoa/GBHueSliderCell.m

@@ -22,7 +22,7 @@
         case 1:
             r = 1 - t;
             g = 1;
-            b = 0;
+            break;
         case 2:
             g = 1;
             b = t;

Cocoa/GBPreferencesWindow.m

@@ -561,7 +561,6 @@
         double max = 0;
         for (JOYAxis *axis in controller.axes) {
             if ((axis.value > 0.5 || (axis.equivalentButtonUsage == button.usage)) && axis.value >= max) {
-                max = axis.value;
                 mapping[@"AnalogUnderclock"] = @(axis.uniqueID);
                 break;
             }