2.4.10 duplicate ISDN symbol

[Keith Owens]

If both st5481 and tpam are compiled into the kernel, hdlc_decode is a
duplicated symbol.

drivers/isdn/hisax/st5481_hdlc.c:int hdlc_decode(struct hdlc_vars *hdlc, const unsigned char *src,
drivers/isdn/hisax/st5481_usb.c:                        status = hdlc_decode(&in->hdlc_state, ptr, len, &count,

drivers/isdn/tpam/tpam_hdlc.c:DWORD hdlc_decode(BYTE * pbyBuffIn, BYTE * pbyBuffOut, DWORD dwLength)
drivers/isdn/tpam/tpam_commands.c:              templen = hdlc_decode(data, tempdata, len);