callouts: switch callout-yaml path to absolute

Most external users of the CALLOUT_YAML use an absolute path, so it
is only through luck that the callouts.py script use to work as it
was previously adding the path to the script onto the YAML parameter.
This behavior doesn't work well with other build systems (ex. Meson)
because they deduce fuller relative paths to dependency files.

Switch the CALLOUTS_YAML default and all associated handling to use
a project-relative path and avoid the magic of adding the script-dir.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I5317bef9175ecb18c0f4e4de2e8d6a7320a3de30
diff --git a/callouts/callouts.py b/callouts/callouts.py
index 3b59587..7ec367b 100755
--- a/callouts/callouts.py
+++ b/callouts/callouts.py
@@ -12,10 +12,11 @@
 
     parser.add_argument(
         '-i', '--callouts_yaml', dest='callouts_yaml',
-        default='callouts-example.yaml', help='input callouts yaml')
+        default=os.path.join(script_dir, 'callouts-example.yaml'),
+        help='input callouts yaml')
     args = parser.parse_args()
 
-    with open(os.path.join(script_dir, args.callouts_yaml), 'r') as fd:
+    with open(args.callouts_yaml, 'r') as fd:
         calloutsMap = yaml.safe_load(fd)
 
         # Render the mako template
diff --git a/configure.ac b/configure.ac
index 2600f60..6a73869 100644
--- a/configure.ac
+++ b/configure.ac
@@ -131,7 +131,7 @@
     [YAML_DIR="None"])
 AC_ARG_VAR(CALLOUTS_YAML, [YAML filepath containing generated callouts.])
 AS_IF([test "x$CALLOUTS_YAML" == "x"], \
-    [CALLOUTS_YAML="callouts-example.yaml"])
+    [CALLOUTS_YAML="callouts/callouts-example.yaml"])
 
 AC_ARG_VAR(ERRLOG_PERSIST_PATH, [Path of directory housing persisted errors.])\
 AS_IF([test "x$ERRLOG_PERSIST_PATH" == "x"],