staging: r8188eu: remove intermediate pframe pointer

The pframe pointer in on_action_public is used only in the definition of
frame_body, which points to the payload of an incoming action frame.

We can use mgmt to locate the action payload and remove the pframe
pointer.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Link: https://lore.kernel.org/r/20221230175326.90617-4-martin@kaiser.cxSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_mlme_ext.c

@@ -3738,8 +3738,7 @@ static unsigned int on_action_public_p2p(struct recv_frame *precv_frame)
 static void on_action_public(struct adapter *padapter, struct recv_frame *precv_frame)
 {
 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)precv_frame->rx_data;
-	u8 *pframe = precv_frame->rx_data;
-	u8 *frame_body = pframe + sizeof(struct ieee80211_hdr_3addr);
+	u8 *frame_body = (u8 *)&mgmt->u;
 	u8 token;
 
 	/* All members of the action enum start with action_code. */