Replace _stp_symbol_snprint usage with _stp_snprint_addr.

Replace _stp_symbol_snprint usage with _stp_snprint_addr.

_stp_snprint_addr is a more generic version of _stp_symbol_snprint.
[u]symdata is now also slightly more exact is offset/sizes returned.

* runtime/sym.c (_stp_symbol_snprint): Removed.
* runtime/sym.h (_STP_SYM_DATA): New define for sym/mod/off/size.
* tapset/context-symbols.stp (probefunc): Use _stp_snprint_addr with
  _STP_SYM_SYMBOL.
  (symname): Likewise.
  (symdata): Use _stp_snprint_addr with _STP_SYM_DATA.
* tapset/ucontext-symbols.stp (usymname): Use _stp_snprint_addr with
  _STP_SYM_SYMBOL.
  (usymdata): Use _stp_snprint_addr with _STP_SYM_DATA.
* testsuite/systemtap.context/uprobe_uaddr.exp: Tweak result_funcs match.