patch 8.2.4024: confusing error message if imported name is used directly

Problem:    Confusing error message if imported name is used directly.
Solution:   Give a better error message.
diff --git a/src/evalvars.c b/src/evalvars.c
index 2de6f22..730c7d1 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -1239,8 +1239,8 @@
 		{
 		    // handle d.key, l[idx], f(expr)
 		    arg_subsc = arg;
-		    if (handle_subscript(&arg, &tv, &EVALARG_EVALUATE, TRUE)
-								       == FAIL)
+		    if (handle_subscript(&arg, name_start, &tv,
+					      &EVALARG_EVALUATE, TRUE) == FAIL)
 			error = TRUE;
 		    else
 		    {
@@ -3955,7 +3955,8 @@
 	{
 	    // handle d.key, l[idx], f(expr)
 	    arg = skipwhite(arg);
-	    n = (handle_subscript(&arg, &tv, &EVALARG_EVALUATE, FALSE) == OK);
+	    n = (handle_subscript(&arg, name, &tv, &EVALARG_EVALUATE,
+								 FALSE) == OK);
 	    if (n)
 		clear_tv(&tv);
 	}