qcacld-3.0: Avoid NULL pointer dereference in lim_send_auth_mgmt_frame

pLimJoinReq will be NULL for the pe session, created when
STA does a successful FT-Preauth with target AP, using LFR
2.0 based roaming.
Any subsequent roaming using this new pe session will cause NULL
pointer dereference.
Hence checking validity of session->pLimJoinReq before accessing.

Change-Id: I47480a4d22c02ce1cc804430f60e8adf7959164e
CRs-Fixed: 2433647

core/mac/src/pe/lim/lim_send_management_frames.c

@@ -2394,7 +2394,8 @@ lim_send_auth_mgmt_frame(struct mac_context *mac_ctx,
 		}
 
 		/* include MDIE in FILS authentication frame */
-		if (session->pLimJoinReq->is11Rconnection &&
+		if (session->pLimJoinReq &&
+		    session->pLimJoinReq->is11Rconnection &&
 		    auth_frame->authAlgoNumber == SIR_FILS_SK_WITHOUT_PFS &&
 		    session->pLimJoinReq->bssDescription.mdiePresent)
 			frame_len += (2 + SIR_MDIE_SIZE);