wlan: Free diag buff only after its allocated.

In pmcWowlAddBcastPattern log_ptr is freed even though log_ptr
is not allocated.
Free buff only after its allocated.

CRs-Fixed: 885162
Change-Id: Ic4b9b52bf01bbb92a818efc6df4faeb611a9fe08
diff --git a/CORE/SME/src/pmc/pmcApi.c b/CORE/SME/src/pmc/pmcApi.c
index 1c2287d..055f0dc 100644
--- a/CORE/SME/src/pmc/pmcApi.c
+++ b/CORE/SME/src/pmc/pmcApi.c
@@ -2173,18 +2173,12 @@
     if(pattern == NULL)
     {
         pmcLog(pMac, LOGE, FL("Null broadcast pattern being passed"));
-#ifdef FEATURE_WLAN_DIAG_SUPPORT
-        WLAN_VOS_DIAG_LOG_FREE(log_ptr);
-#endif
         return eHAL_STATUS_FAILURE;
     }
 
     if( pSession == NULL)
     {
         pmcLog(pMac, LOGE, FL("Session not found "));
-#ifdef FEATURE_WLAN_DIAG_SUPPORT
-        WLAN_VOS_DIAG_LOG_FREE(log_ptr);
-#endif
         return eHAL_STATUS_FAILURE;
     }