curses: fix garbling when chtype != long

curses: fix garbling when chtype != long

Qemu currently assumes that chtype is typedef'd to unsigned long, but
this is not necessarily the case (ncurses, for instance, can configure
this at build-time).  This patch uses the predefined chtype if qemu is
configured for curses support and falls back to unsigned long otherwise.

Fixes bug 568614.

Signed-off-by: Devin J. Pohly <djpohly+launchpad@gmail.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>