wlan:Fix for STA Association Failure using WEP Keys 2, 3 and 4

driver considering the default WEP key index is always Zero(key id =1),
Populating the proper index which is resolving the assosiation failures
with WEP key index 2,3,4

CRs-fixed: 404443, 404446
Change-Id: I0298b3579a33b33d235511ab227dc804de5a51c1
diff --git a/CORE/HDD/src/wlan_hdd_cfg80211.c b/CORE/HDD/src/wlan_hdd_cfg80211.c
index 6557ccc..28b9b17 100644
--- a/CORE/HDD/src/wlan_hdd_cfg80211.c
+++ b/CORE/HDD/src/wlan_hdd_cfg80211.c
@@ -2821,6 +2821,9 @@
 
         pWextState->roamProfile.Keys.KeyLength[key_index] = (u8)params->key_len;
 
+        pWextState->roamProfile.Keys.defaultIndex = key_index;
+
+
         vos_mem_copy(&pWextState->roamProfile.Keys.KeyMaterial[key_index][0], 
                 params->key, params->key_len);