yanglint BUGFIX module can be added additionally

... to the context defined by --yang-library-file parameter.
diff --git a/tools/lint/main_ni.c b/tools/lint/main_ni.c
index 2b016ba..b836ff1 100644
--- a/tools/lint/main_ni.c
+++ b/tools/lint/main_ni.c
@@ -424,14 +424,12 @@
                 goto error;
             }
 
+            mod = NULL;
             if (c->yang_lib_file) {
                 /* just get the module, it should already be parsed */
                 mod = ly_ctx_get_module_implemented(c->ctx, module);
-                if (!mod) {
-                    YLMSG_E("Schema module \"%s\" not implemented in yang-library data.\n", module);
-                    goto error;
-                }
-            } else {
+            }
+            if (!mod) {
                 /* add temporarily also the path of the module itself */
                 if (ly_ctx_set_searchdir(c->ctx, dir) == LY_EEXIST) {
                     path_unset = 0;
diff --git a/tools/lint/tests/non-interactive/yang_library_file.test b/tools/lint/tests/non-interactive/yang_library_file.test
index 0667263..bd95978 100644
--- a/tools/lint/tests/non-interactive/yang_library_file.test
+++ b/tools/lint/tests/non-interactive/yang_library_file.test
@@ -11,4 +11,8 @@
     ly_cmd "-Y $ddir/modimp_type_ctx.xml -p $mdir -i -i -l" "I modimp-type.*I modtypedef"
 } {}
 
+test ylf_augment_ctx {Setup context by yang-library-file and augment module} {
+    ly_cmd "-Y $ddir/modconfig_ctx.xml -p $mdir -f tree $mdir/modconfig.yang $mdir/modconfig-augment.yang" "mca:alf"
+} {}
+
 cleanupTests