Remove <linux/input.h> include from test/x11comp.c

libxkbcommon 0.4.3 introduces a new test, x11comp, which does not build
on non-Linux OSes because of the unconditional <linux/input.h> include.

This seems not needed even on Linux, so attached there is a simple patch
to remove it.

https://bugs.freedesktop.org/show_bug.cgi?id=83551

Signed-off-by: Ran Benita <ran234@gmail.com>

test/x11comp.c

@@ -28,7 +28,6 @@
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/wait.h>
-#include <linux/input.h>
 
 #include "test.h"
 #include "xkbcommon/xkbcommon-x11.h"