Fixed fdoc_sourcelinks: Error opening issues

Ticket: CFE-4570
Signed-off-by: Ihor Aleksandrychiev <ihor.aleksandrychiev@northern.tech>

Author: aleksandrychev

generator/_scripts/cfdoc_sourcelinks.py

@@ -118,7 +118,7 @@ def addLinkToSource(file_name, config):
     unexpanded_macro = unexpandedMacroRegex()
 
     error_count = 0
-    html_file = config["CFE_DIR"] + "/" + html_file
+    html_file = config["CFE_DIR"] + "/" + html_file + "/index.html"
     try:
         in_file = open(html_file, "r")
         lines = in_file.readlines()