paging: fix paging attemt rate counter

The rate counter BSC_CTR_PAGING_ATTEMPTED does not increment when
a paging request is sent to the BSC. The reson for this is that the
function call to rate_ctr_inc() is located in a dead code section.

- Move the function call to rate_ctr_inc() to osmo_bsc_bssmap.c.
  incremanet on any paging attempt (valid or not) that is recived
  on the A-Interface.

- Remove dead code from paging.c

Change-Id: Iec3eb6724bc655806c3ce3c28448069590d99f91
2 files changed