Cleanup

Thanks to glfwGetKeyScancode we can now pass only a scancode to the
platform layer for glfwGetKeyName.

src/wl_window.c

@@ -721,7 +721,7 @@ void _glfwPlatformSetCursorMode(_GLFWwindow* window, int mode)
     _glfwPlatformSetCursor(window, window->wl.currentCursor);
 }
 
-const char* _glfwPlatformGetKeyName(int key, int scancode)
+const char* _glfwPlatformGetScancodeName(int scancode)
 {
     // TODO
     return NULL;