qcacmn: Fix memory leak and NULL access in scm_add_rnr_channel_db

In scm_add_rnr_channel_db, if pointer channel is NULL, it should return.
Allocate rnr_node buffer whenever it is used, otherwise memory leak
happens if the BSS channel is not 6Ghz.

Change-Id: Iecba2453c2e9cdf9301826e0e11f740190616110
CRs-Fixed: 2601014
1 file changed