[cogl/wip/hadess/automake-1.16] Return the correct value

[Emmanuele Bassi <ebassi src gnome org>]

commit db85223e442a71c79d35259b9631f9000df7b44b
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Thu Jun 4 12:18:26 2020 +0100

    Return the correct value
    
    NULL is not a CoglBool value.

 cogl/driver/gl/cogl-framebuffer-gl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/cogl/driver/gl/cogl-framebuffer-gl.c b/cogl/driver/gl/cogl-framebuffer-gl.c
index b487a4ce..5670a256 100644
--- a/cogl/driver/gl/cogl-framebuffer-gl.c
+++ b/cogl/driver/gl/cogl-framebuffer-gl.c
@@ -801,7 +801,7 @@ _cogl_offscreen_gl_allocate (CoglOffscreen *offscreen,
 
   _COGL_RETURN_VAL_IF_FAIL (offscreen->texture_level <
                             _cogl_texture_get_n_levels (offscreen->texture),
-                            NULL);
+                            FALSE);
 
   _cogl_texture_get_level_size (offscreen->texture,
                                 offscreen->texture_level,