patch 8.2.1152: Vim9: function reference is missing script prefix

Problem:    Vim9: function reference is missing script prefix.
Solution:   Use the actual function name instead of the name searched for in
            the script context. (closes #6412)
diff --git a/src/vim9compile.c b/src/vim9compile.c
index ff6668f..07e0d27 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -2676,7 +2676,8 @@
     if (ufunc == NULL)
 	return FAIL;
 
-    return generate_PUSHFUNC(cctx, vim_strsave(name), ufunc->uf_func_type);
+    return generate_PUSHFUNC(cctx, vim_strsave(ufunc->uf_name),
+							  ufunc->uf_func_type);
 }
 
 /*