cosmetics: consistently use [u]int64_t

Removes mixed usage of (unsigned) long long and INT64.
Fixes Issue #208.

Change-Id: I220d3ed5ce4bb1280cd38bb3715f208ce23cf83a
diff --git a/vp8/vp8_dx_iface.c b/vp8/vp8_dx_iface.c
index 13a072b..ad8cd5e 100644
--- a/vp8/vp8_dx_iface.c
+++ b/vp8/vp8_dx_iface.c
@@ -427,7 +427,7 @@
     if (!res && ctx->pbi)
     {
         YV12_BUFFER_CONFIG sd;
-        INT64 time_stamp = 0, time_end_stamp = 0;
+        int64_t time_stamp = 0, time_end_stamp = 0;
         vp8_ppflags_t flags = {0};
 
         if (ctx->base.init_flags & VPX_CODEC_USE_POSTPROC)