Fix build errors on Windows.

Since this is a C file, variables must be declared at the top of the function
so I'm moving the fix for the warning (inst = NULL) to the bottom of the funciton.
Otherwise, the compiler will complain when it sees int i; on systems that do
not have WEBRTC_BIG_ENDIAN defined.
Review URL: http://webrtc-codereview.appspot.com/139005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@494 4adac7df-926f-26a2-2b94-8c16560cd09d

src/modules/audio_coding/codecs/PCM16B/main/source/pcm16b.c

@@ -68,7 +68,6 @@ WebRtc_Word16 WebRtcPcm16b_DecodeW16(void *inst,
                                      WebRtc_Word16 *speechOut16b,
                                      WebRtc_Word16* speechType)
 {
-  (void)(inst = NULL);
 #ifdef WEBRTC_BIG_ENDIAN
     WEBRTC_SPL_MEMCPY_W8(speechOut16b, speechIn16b, ((len*sizeof(WebRtc_Word16)+1)>>1));
 #else
@@ -81,6 +80,10 @@ WebRtc_Word16 WebRtcPcm16b_DecodeW16(void *inst,
 #endif
 
     *speechType=1;
+
+    // Avoid warning.
+    (void)(inst = NULL);
+
     return(len>>1);
 }