libweston: Properly namespace modules entrypoint

Use different functions so we cannot load a libweston common module in
weston directly or the other way around.

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
Reviewed-by: Daniel Stone <daniels@collabora.com>

tests/plugin-registry-test.c

@@ -28,6 +28,7 @@
 #include <assert.h>
 
 #include "compositor.h"
+#include "compositor/weston.h"
 #include "plugin-registry.h"
 
 static void

tests/surface-global-test.c

@@ -29,6 +29,7 @@
 #include <stdint.h>
 
 #include "compositor.h"
+#include "compositor/weston.h"
 
 static void
 surface_to_from_global(void *data)

tests/surface-screenshot.c

@@ -34,6 +34,7 @@
 #include <linux/input.h>
 
 #include "compositor.h"
+#include "compositor/weston.h"
 #include "file-util.h"
 
 static char *

tests/surface-test.c

@@ -29,6 +29,7 @@
 #include <assert.h>
 
 #include "compositor.h"
+#include "compositor/weston.h"
 
 static void
 surface_transform(void *data)