qcacld-3.0: Fix memory leak in mac_open

Make sure to free cfg resource in allocated during
cfg_init when case of pe_open failure happen.

Change-Id: I651585dabec344253fb3015d974f9f4685d24304
CRs-Fixed: 2027588
diff --git a/core/mac/src/sys/legacy/src/system/src/mac_init_api.c b/core/mac/src/sys/legacy/src/system/src/mac_init_api.c
index 529510a..3d4a6ee 100644
--- a/core/mac/src/sys/legacy/src/system/src/mac_init_api.c
+++ b/core/mac/src/sys/legacy/src/system/src/mac_init_api.c
@@ -141,8 +141,10 @@
 	p_mac->first_scan_done = false;
 
 	status =  pe_open(p_mac, cds_cfg);
-	if (eSIR_SUCCESS != status)
+	if (eSIR_SUCCESS != status) {
 		pe_err("pe_open() failure");
+		cfg_de_init(p_mac);
+	}
 
 	return status;
 }