[svn r124] Fixed another D vararg + return in ptr bug.

Fixed some nested function calls failed to resolve the context ptr.

test/strings2.d

@@ -0,0 +1,15 @@
+module strings2;
+
+import std.string;
+import std.stdio;
+
+void main()
+{
+    int i = 32;
+    auto str = format(i);
+    writefln(str);
+
+    long l = 123123;
+    str = format(l);
+    writefln(str);
+}