stagefright amrwbenc: Remove a useless check

Since the Length field is unsigned, the comparison will always
be false. The corresponding code in the aac encoder doesn't have
any check for Length.

This avoids a warning about comparison always being false.

Change-Id: I57c28ff9d09cb9ac4effeaeb40db608ab976acc6

Author: mstorsjo

media/libstagefright/codecs/amrwbenc/src/voAMRWBEnc.c

@@ -1702,7 +1702,7 @@ VO_U32 VO_API voAMRWB_SetInputData(
 	gData = (Coder_State *)hCodec;
 	stream = gData->stream;
 
-	if(NULL == pInput || NULL == pInput->Buffer || 0 > pInput->Length)
+	if(NULL == pInput || NULL == pInput->Buffer)
 	{
 		return VO_ERR_INVALID_ARG;
 	}