patch 8.2.4023: using uninitialized variable

Problem:    Using uninitialized variable.
Solution:   Initialize "ufunc" also when an item is not exported.
diff --git a/src/vim9script.c b/src/vim9script.c
index 815ded1..81f3967 100644
--- a/src/vim9script.c
+++ b/src/vim9script.c
@@ -565,6 +565,7 @@
     if (idx >= 0)
     {
 	sv = ((svar_T *)script->sn_var_vals.ga_data) + idx;
+	*ufunc = NULL;
 	if (!sv->sv_export)
 	{
 	    if (verbose)
@@ -572,7 +573,6 @@
 	    return -1;
 	}
 	*type = sv->sv_type;
-	*ufunc = NULL;
     }
     else
     {