Silence GCC when incorrectly complaining that the "line" variable could be used

without having been initialized.

Originally committed as revision 7711 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/snow.c

@@ -3547,7 +3547,7 @@ static void correlate_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand
 
 //    START_TIMER
 
-    DWTELEM * line;
+    DWTELEM * line=0; // silence silly "could be used without having been initialized" warning
     DWTELEM * prev;
 
     if (start_y != 0)