vl/idct: cleanup all idct buffers

Code should loop through and cleanup the three (VL_NUM_COMPONENTS) idct
buffers, rather than doing the first one three times.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>

src/gallium/auxiliary/vl/vl_mpeg12_decoder.c

@@ -198,7 +198,7 @@ cleanup_idct_buffer(struct vl_mpeg12_buffer *buf)
    assert(buf);
 
    for (i = 0; i < 3; ++i)
-      vl_idct_cleanup_buffer(&buf->idct[0]);
+      vl_idct_cleanup_buffer(&buf->idct[i]);
 }
 
 static bool