clients/simple-egl: include weston-egl-ext.h correctly

weston-egl-ext.h was moved to shared/ in
ffff92d592

Use the correct include path, so that Meson build does not need to add
../shared to the include path just for this.

Signed-off-by: Pekka Paalanen <pq@iki.fi>

clients/simple-egl.c

@@ -50,7 +50,7 @@
 
 #include "shared/helpers.h"
 #include "shared/platform.h"
-#include "weston-egl-ext.h"
+#include "shared/weston-egl-ext.h"
 
 struct window;
 struct seat;