qcacld-3.0: Fix the potential buffer overflow issue

Add check in function 'policy_mgr_get_sbs_channels' to restrict the
array index out of bounds.

Change-Id: I387b666095107faf284e35f073dfe856d38323d3
CRs-Fixed: 2776966

components/cmn_services/policy_mgr/src/wlan_policy_mgr_core.c

@@ -1862,7 +1862,8 @@ static QDF_STATUS policy_mgr_get_sbs_channels(
 		/* Get list of valid sbs channels for the current
 		 * connected channel
 		 */
-		for (j = 0; j < available_5g_channels_len; j++) {
+		for (j = 0; (j < available_5g_channels_len) &&
+		     (j < NUM_CHANNELS); j++) {
 			if (WLAN_REG_IS_FREQUENCY_VALID_5G_SBS(
 			    cur_5g_ch_freq, available_5g_ch_freqs[j])) {
 				ch_freq_list[num_channels++] =