Changes

codec: make osmo_hr_check_sid() more efficient

The operation of checking an HRv1 codec frame for the possibility
of a perfect, error-free SID entails checking the last 79 bits
out of 112, to see if they are all 1s.  This operation can be done
much more efficiently without using bitvec.

Change-Id: Ib14204102c03c14d6c5aab42b0ffbef2c3dda3fd