* utils.c (safe_strerror): Use xsnprintf instead of sprintf.

* utils.c (safe_strerror): Use xsnprintf instead of sprintf.
(decimal2str, octal2str): Change to return a string allocated by
get_cell.  Use xsnprint instead of snprintf.
(paddr_u, paddr_d): Adjust for changed calling convention of
decimal2str.
(phex, phex_nz, hex_string): Use xsnprintf instead of snprintf.
(int_string): Likewise.  Adjust for changed calling convention of
decimal2str and octal2str.