stagefright: ACodec: query color format support on specific port

This field was uninitialized prior.
Some components did not validate this field resulting in an infinite
query.

Bug: 27114487
Change-Id: Ic262482a17e675c4e5f198661fad96269cf1febc
diff --git a/media/libstagefright/ACodec.cpp b/media/libstagefright/ACodec.cpp
index 73177c1..aa40c17 100644
--- a/media/libstagefright/ACodec.cpp
+++ b/media/libstagefright/ACodec.cpp
@@ -7066,7 +7066,7 @@
         // prefix "flexible" standard ones with the flexible equivalent
         OMX_VIDEO_PARAM_PORTFORMATTYPE portFormat;
         InitOMXParams(&portFormat);
-        param.nPortIndex = isEncoder ? kPortIndexInput : kPortIndexOutput;
+        portFormat.nPortIndex = isEncoder ? kPortIndexInput : kPortIndexOutput;
         Vector<uint32_t> supportedColors; // shadow copy to check for duplicates
         for (portFormat.nIndex = 0;; ++portFormat.nIndex)  {
             status_t err = omx->getParameter(