Fixes -Wformat warning in xrestop_display
xrestop.c: In function ‘xrestop_display’: xrestop.c:551:32: warning: format ‘%x’ expects argument of type ‘unsigned int’, but argument 4 has type ‘XID’ {aka ‘long unsigned int’} [-Wformat=] 551 | mvprintw(i+5, 0, "%.7x %4d %4d %4d %4d %4d %4d %7s %7s %7s %5s %s", | ~~~^