libcamera: device_enumerator_udev: Initialize monitor_ and notifier_ to nullptr

The monitor_ and notifier_ pointers are acted on in the destructor if
not set to nullptr, the pointers are however first initialized in
init() and enumerate(). Avoid acting on uninitialized pointers by
initializing them to nullptr in the constructor.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Umang Jain <email@uajain.com>

src/libcamera/device_enumerator_udev.cpp

@@ -27,7 +27,7 @@ namespace libcamera {
 LOG_DECLARE_CATEGORY(DeviceEnumerator)
 
 DeviceEnumeratorUdev::DeviceEnumeratorUdev()
-	: udev_(nullptr)
+	: udev_(nullptr), monitor_(nullptr), notifier_(nullptr)
 {
 }