idevicebackup4: add more error checking to mb2_handle_receive_files
idevicebackup4: add more error checking to mb2_handle_receive_files

Tatsh/libimobiledevice,libimobiledevice-win32/libimobiledevice,patweb/libimobiledevice,Tatsh/libimobiledevice,kalev/libimobiledevice,patweb/libimobiledevice,libimobiledevice/libimobiledevice,kalev/libimobiledevice,libimobiledevice-win32/libimobiledevice,Tatsh/libimobiledevice,libimobiledevice-win32/libimobiledevice,upbit/libimobiledevice,upbit/libimobiledevice,upbit/libimobiledevice,Tatsh/libimobiledevice,libimobiledevice/libimobiledevice,kalev/libimobiledevice,libimobiledevice-win32/libimobiledevice,patweb/libimobiledevice