staging: r8188eu: remove free_xmit_priv field from struct hal_ops

Remove free_xmit_priv function pointer field from struct hal_ops definition
in include/hal_intf.h, as it is now no longer used anywhere in the driver.
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20210818234253.208271-7-phil@philpotter.co.ukSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/include/hal_intf.h

@@ -139,7 +139,6 @@ struct hal_ops {
 	u32	(*inirp_deinit)(struct adapter *padapter);
 
 	s32	(*init_xmit_priv)(struct adapter *padapter);
-	void	(*free_xmit_priv)(struct adapter *padapter);
 
 	s32	(*init_recv_priv)(struct adapter *padapter);
 	void	(*free_recv_priv)(struct adapter *padapter);