The call to _nc_init_acs in min_panel_init() will, indeed, attempt
to output the ena_acs string (among other activities) if it's set.

However, it may output it using putc to the stdio FILE handle.

That may, or may not, be the actual output device that we are using.

In any case, to be sure we end up with ena_acs having been output
at least once to the intended output device, flush all output streams
after calling _nc_init_acs and then output ena_acs once more (if
it's set), just in case.

To be clear, the call to _nc_init_acs MUST still be made regardless
of whether it outputs ena_acs because _nc_init_acs performs various
other tasks required to make the alternate character set work --
outputting ena_acs (when set) is just one of the things it does.

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>