staging: r8723au: remove unneeded forward function declarations

Remove unneeded forward function declarations.

Addresses checkpatch.pl:
WARNING: externs should be avoided in .c files
Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723au/core/rtw_efuse.c

@@ -274,7 +274,6 @@ u8 EFUSE_Read1Byte23a(struct rtw_adapter *Adapter, u16 Address)
 }
 
 /* Copy from WMAC fot EFUSE write 1 byte. */
-void EFUSE_Write1Byte(struct rtw_adapter *Adapter, u16 Address, u8 Value);
 void EFUSE_Write1Byte(struct rtw_adapter *Adapter, u16 Address, u8 Value)
 {
 	u8	Bytetemp = {0x00};
@@ -502,7 +501,6 @@ int rtw_BT_efuse_map_read23a(struct rtw_adapter *padapter,
 }
 
 /* Read All Efuse content */
-void Efuse_ReadAllMap(struct rtw_adapter *pAdapter, u8 efuseType, u8 *Efuse);
 void Efuse_ReadAllMap(struct rtw_adapter *pAdapter, u8 efuseType, u8 *Efuse)
 {
 	u16	mapLen = 0;