cfg80211: remove @gfp parameter from cfg80211_rx_mgmt()

In the cfg80211_rx_mgmt(), parameter @gfp was used for the memory allocation.
But, memory get allocated under spin_lock_bh(), this implies atomic context.
So, one can't use GFP_KERNEL, only variants with no __GFP_WAIT. Actually, in all
occurrences GFP_ATOMIC is used (wil6210 use GFP_KERNEL by mistake),
and it should be this way or warning triggered in the memory allocation code.

Remove @gfp parameter as no actual choice exist, and use hard coded
GFP_ATOMIC for memory allocation.

Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/ath/wil6210/wmi.c

@@ -350,7 +350,7 @@ static void wmi_evt_rx_mgmt(struct wil6210_priv *wil, int id, void *d, int len)
 		}
 	} else {
 		cfg80211_rx_mgmt(wil->wdev, freq, signal,
-				 (void *)rx_mgmt_frame, d_len, 0, GFP_KERNEL);
+				 (void *)rx_mgmt_frame, d_len, 0);
 	}
 }