dm-ima: Fail more gracefully in dm_ima_measure_on_*

dm-ima: Fail more gracefully in dm_ima_measure_on_*

In all the dm_ima_measure_on_* functions besides
dm_ima_measure_on_table_load(), even if measuring the event fails, it's
still possible to update dm->ima, so that it continues to correctly
track the device state. This means that one measurement failure won't
cause future measurements to record the wrong data.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>