staging: r8188eu: limit rtw_wx_read_rf to path a

Commit 3b011b09 ("staging: r8188eu: limit rf register writes to
path a") limits rf register writes by private ioctls to RF_PATH_A.
Apart from private ioctls, the rest of the driver uses only path a.

This patch limits rf register reads by the private ioctl 0x0D, which
calls rtw_wx_read_rf, to path a.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220212161737.381841-7-martin@kaiser.cxSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/os_dep/ioctl_linux.c

@@ -2063,8 +2063,11 @@ static int rtw_wx_read_rf(struct net_device *dev,
 	u32 path, addr, data32;
 
 	path = *(u32 *)extra;
+	if (path != RF_PATH_A)
+		return -EINVAL;
+
 	addr = *((u32 *)extra + 1);
-	data32 = rtl8188e_PHY_QueryRFReg(padapter, path, addr, 0xFFFFF);
+	data32 = rtl8188e_PHY_QueryRFReg(padapter, RF_PATH_A, addr, 0xFFFFF);
 	/*
 	 * IMPORTANT!!
 	 * Only when wireless private ioctl is at odd order,
@@ -3626,7 +3629,7 @@ static int rtw_dbg_port(struct net_device *dev,
 			break;
 		}
 		rtl8188e_PHY_SetRFReg(padapter, arg, 0xffffffff, extra_arg);
-		DBG_88E("write RF_reg path(0x%02x), offset(0x%x), value(0x%08x)\n", minor_cmd, arg, rtl8188e_PHY_QueryRFReg(padapter, minor_cmd, arg, 0xffffffff));
+		DBG_88E("write RF_reg path(0x%02x), offset(0x%x), value(0x%08x)\n", RF_PATH_A, arg, rtl8188e_PHY_QueryRFReg(padapter, RF_PATH_A, arg, 0xffffffff));
 		break;
 
 	case 0x76: