Cocoa: Fix segfault querying joystick elements

It is reportedly possible for IOHIDDeviceCopyMatchingElements to return
NULL on macOS 13 if the application lacks input monitoring permissions.

This commit only prevents the segfault.  More work will be needed to
correctly handle this situation, including Game Controller support.

Related to #2320
Closes #2321

src/cocoa_joystick.m

@@ -136,6 +136,14 @@ static void matchCallback(void* context,
             return;
     }
 
+    CFArrayRef elements =
+        IOHIDDeviceCopyMatchingElements(device, NULL, kIOHIDOptionsTypeNone);
+
+    // It is reportedly possible for this to fail on macOS 13 Ventura
+    // if the application does not have input monitoring permissions
+    if (!elements)
+        return;
+
     axes    = CFArrayCreateMutable(NULL, 0, NULL);
     buttons = CFArrayCreateMutable(NULL, 0, NULL);
     hats    = CFArrayCreateMutable(NULL, 0, NULL);
@@ -179,9 +187,6 @@ static void matchCallback(void* context,
                 name[8], name[9], name[10]);
     }
 
-    CFArrayRef elements =
-        IOHIDDeviceCopyMatchingElements(device, NULL, kIOHIDOptionsTypeNone);
-
     for (CFIndex i = 0;  i < CFArrayGetCount(elements);  i++)
     {
         IOHIDElementRef native = (IOHIDElementRef)