* include/freetype/ftmodapi.h (FT_DebugHook_Func): Return error.

Fix a warning by adding a return value as in `TT_RunIns',
which should not be a compatibility issue.
diff --git a/ChangeLog b/ChangeLog
index 78d99e1..f5bd68f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2019-06-12  Alexei Podtelezhnikov  <apodtele@gmail.com>
+
+	* include/freetype/ftmodapi.h (FT_DebugHook_Func): Return error.
+
+	Fix a warning by adding a return value as in `TT_RunIns',
+	which should not be a compatibility issue. 
+
 2019-06-11  Alexei Podtelezhnikov  <apodtele@gmail.com>
 
 	* src/truetype/ttobjs.c (tt_check_trickyness_family): Add `const'.
diff --git a/include/freetype/ftmodapi.h b/include/freetype/ftmodapi.h
index 88488bf..8d039c4 100644
--- a/include/freetype/ftmodapi.h
+++ b/include/freetype/ftmodapi.h
@@ -623,7 +623,7 @@
    *     it is bytecode interpreter's execution context, `TT_ExecContext`,
    *     which is declared in FreeType's internal header file `tttypes.h`.
    */
-  typedef void
+  typedef FT_Error
   (*FT_DebugHook_Func)( void*  arg );