dm integrity: introduce a function add_new_range_and_wait()

Introduce a function add_new_range_and_wait() in order to avoid
repetitive code.  It will be used in the following commit.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
1 file changed