[libgda/LIBGDA_5.2] Fix DOC_SOURCE_DIR path

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 2b4a7a3b55f6bef24c2a8a8a39f83d5da0e02551
Author: Daniel Espinosa <esodan gmail com>
Date:   Sat Sep 22 21:58:17 2018 -0500

    Fix DOC_SOURCE_DIR path

 doc/C/Makefile.am | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/doc/C/Makefile.am b/doc/C/Makefile.am
index c619ae148..0158edc0f 100644
--- a/doc/C/Makefile.am
+++ b/doc/C/Makefile.am
@@ -15,7 +15,7 @@ SCAN_OPTIONS=--deprecated-guards="GDA_DISABLE_DEPRECATED"
 SCANGOBJ_OPTIONS=
 
 # The directory containing the source code. Relative to $(srcdir)
-DOC_SOURCE_DIR=../..
+DOC_SOURCE_DIR=$(top_srcdir)
 
 # Add the builddir to the HTML path so that version.xml is found
 MKHTML_OPTIONS=--path="$(abs_srcdir)"