mktemp(): bugfix: quote variable
mktemp(): bugfix: quote variable

libexec/modernish/sys/base/mktemp.mm:
- Well, that's embarrassing: I forgot to quote me a lil variable.
  In my defence, once I bothered to test mktemp() without 'use
  safe' (i.e. with field splitting & globbing enabled), this
  demonstrated the value of robust validation and bounds checking
  in all aspects of the library: the program died gracefully once
  'endswith' got too many arguments, so the bug & fix was obvious.

modernish/modernish