udev_enumerate_add_match_tag() and udev_monitor_filter_add_match_tag()
are mostly optimizations, hence simply skip these calls if they are not
available in the installed version of libudev.
This should fix the build on older versions of udev.
[airlied: fixes tinderbox failures on RHEL6]
Signed-off-by: Lennart Poettering <lennart@poettering.net>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Tested-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Keith Packard <keithp@keithp.com>