brcmfmac: Fix exception handling.

In some exception situations the ifp->vif was not properly assigned
which could result in crash.
Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c

@@ -6332,6 +6332,7 @@ struct brcmf_cfg80211_info *brcmf_cfg80211_attach(struct brcmf_pub *drvr,
 priv_out:
 	wl_deinit_priv(cfg);
 	brcmf_free_vif(vif);
+	ifp->vif = NULL;
 wiphy_out:
 	brcmf_free_wiphy(wiphy);
 	return NULL;