Everywhere: Prefer using {:#x} over 0x{:x}

We have a dedicated format specifier which adds the "0x" prefix, so
let's use that instead of adding it manually.

Kernel/Graphics/VirtIOGPU/GPU.cpp

@@ -69,7 +69,7 @@ bool GPU::handle_device_config_change()
         clear_pending_events(VIRTIO_GPU_EVENT_DISPLAY);
     }
     if (events & ~VIRTIO_GPU_EVENT_DISPLAY) {
-        dbgln("GPU: Got unknown device config change event: 0x{:x}", events);
+        dbgln("GPU: Got unknown device config change event: {:#x}", events);
         return false;
     }
     return true;