Fix ffs_zu() compilation error on MinGW.

This regression was caused by 9f4ee6034c3ac6a8c8b5f9a0d76822fb2fd90c41
(Refactor jemalloc_ffs*() into ffs_*().).
diff --git a/include/jemalloc/internal/util.h b/include/jemalloc/internal/util.h
index 031f804..b8885bf 100644
--- a/include/jemalloc/internal/util.h
+++ b/include/jemalloc/internal/util.h
@@ -168,10 +168,12 @@
 ffs_zu(size_t bitmap)
 {
 
-#if LG_SIZEOF_PTR == LG_SIZEOF_LONG
-	return (ffs_lu(bitmap));
-#elif LG_SIZEOF_PTR == LG_SIZEOF_INT
+#if LG_SIZEOF_PTR == LG_SIZEOF_INT
 	return (ffs_u(bitmap));
+#elif LG_SIZEOF_PTR == LG_SIZEOF_LONG
+	return (ffs_lu(bitmap));
+#elif LG_SIZEOF_PTR == LG_SIZEOF_LONG_LONG
+	return (ffs_llu(bitmap));
 #else
 #error No implementation for size_t ffs()
 #endif