In existing previous code, pdch->ulc would be freed in
gprs_rlcmac_pdch::free_resources() when it became disabled as per PCUIF
info_ind (for instance, when a DYN TS is switched PDCH->SDCCH8).
However, pdch->ulc was so far only allocated during pdch_init, which is
only called during bts_alloc() time.
Hence, after first info_ind disabling it, if it became again enabled
(again by info_ind re-enabling it after SDCCH8 was not longer in use),
the pdch->ulc would be used again but it would point to freed memory.
Let's rearrange how/when resources are freed to make it more logical.
With this patch, pdch internal resources are freed upon ->disable(), and
re-allocated upon ->enable().
Change-Id: Id51f5f6a54ac9f24b784c17bc360ac38f5726fc7
Pau Espin
4f67a9bf46