qcacld-3.0: Free allocated memory in wma_unified_link_radio_stats_event_handler

In the file wma_unified_radio_tx_power_level_stats_event_handler ,
the driver allocates  memory to rs_results->tx_time_per_power_level ,
also in api wma_unified_link_radio_stats_event_handler ,
rs_results->channels , without checking a previous allocated
memory for the same . Also the driver makes the pointers
rs_results->tx_time_per_power_level and rs_results->channels
as null without a prior check , which results in a memory leak.
Fix is to add a check for rs_results->channels and
rs_results->tx_time_per_power_level for NULL , and free
the already allocated memory for the same.

Change-Id: I02af53454270239bf68446a727b735c8ef10d434
CRs-Fixed: 2150714

core/wma/src/wma_utils.c

@@ -1706,12 +1706,17 @@ static int wma_unified_link_radio_stats_event_handler(void *handle,
 	rs_results->onTimePnoScan = radio_stats->on_time_pno_scan;
 	rs_results->onTimeHs20 = radio_stats->on_time_hs20;
 	rs_results->total_num_tx_power_levels = 0;
-	rs_results->tx_time_per_power_level = NULL;
+	if (rs_results->tx_time_per_power_level) {
+		qdf_mem_free(rs_results->tx_time_per_power_level);
+		rs_results->tx_time_per_power_level = NULL;
+	}
+	if (rs_results->channels) {
+		qdf_mem_free(rs_results->channels);
+		rs_results->channels = NULL;
+	}
 	rs_results->numChannels = radio_stats->num_channels;
 	rs_results->on_time_host_scan = radio_stats->on_time_host_scan;
 	rs_results->on_time_lpi_scan = radio_stats->on_time_lpi_scan;
-	rs_results->channels = NULL;
-
 	if (rs_results->numChannels) {
 		rs_results->channels = (tSirWifiChannelStats *) qdf_mem_malloc(
 					radio_stats->num_channels *