qcacmn: Fix issues in random channel selection algorithm

Remove dummy function dfs_remove_cur_ch_from_list(). This logic is already
implemented in dfs_apply_rules().

In dfs_apply_rules()/dfs_apply_rules_for_freq(), skip all the HT20 channels
of the curent channel when DFS_RANDOM_CH_FLAG_NO_CURR_OPE_CH flag is set.

In dfs_prepare_random_channel_for_freq(), allocate correct size of memory
for leakage_adjusted_lst array.

Use DFS_80_NUM_SUB_CHANNEL macro instead of DFS_80_NUM_SUB_CHANNEL_FREQ to
choose correct 80MHz channel.

Change-Id: Ie318d667ff1b0caef3032b7aa57f0ddfb7e1f1a7
CRs-Fixed: 2570055

umac/dfs/dispatcher/inc/wlan_dfs_utils_api.h

@@ -472,7 +472,7 @@ QDF_STATUS utils_dfs_get_random_channel(struct wlan_objmgr_pdev *pdev,
 #endif
 
 /**
- * utils_dfs_get_random_channel() - Get random channel.
+ * utils_dfs_get_random_channel_for_freq() - Get random channel.
  * @pdev: Pointer to DFS pdev object.
  * @flags: random channel selection flags.
  * @ch_params: current channel params.