parser yang BUGFIX allow in/out without substatements

Refs sysrepo/sysrepo#3117
diff --git a/src/parser_yang.c b/src/parser_yang.c
index dd84480..b81cf60 100644
--- a/src/parser_yang.c
+++ b/src/parser_yang.c
@@ -804,7 +804,8 @@
             MOVE_INPUT(ctx, 1);
             goto extension;
         case '{':
-            /* allowed only for input and output statements which can be without arguments */
+        case ';':
+            /* allowed only for input and output statements which are without arguments */
             if ((*kw == LY_STMT_INPUT) || (*kw == LY_STMT_OUTPUT)) {
                 break;
             }
@@ -2860,11 +2861,6 @@
         YANG_READ_SUBSTMT_NEXT_ITER(ctx, kw, word, word_len, inout_p->exts, ret, cleanup);
     }
 
-    if (!inout_p->child) {
-        LOGVAL_PARSER(ctx, LY_VCODE_MISSTMT, "data-def-stmt", lyplg_ext_stmt2str(inout_kw));
-        return LY_EVALID;
-    }
-
 cleanup:
     return ret;
 }