avcodec/mpegvideo_motion: Handle edge emulation even without unrestricted_mv

Fixes out of array reads
Fixes part of: MSVR 440 (the other issues seem to have been fixed already)
Found-by: Jeremy Brown (jerbrown) of ReSP
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/mpegvideo_motion.c

@@ -209,7 +209,7 @@ static inline int hpel_motion(MpegEncContext *s,
         dxy |= (motion_y & 1) << 1;
     src += src_y * s->linesize + src_x;
 
-    if (s->unrestricted_mv && (s->flags & CODEC_FLAG_EMU_EDGE)) {
+    if (s->flags & CODEC_FLAG_EMU_EDGE) {
         if ((unsigned)src_x > FFMAX(s->h_edge_pos - (motion_x & 1) - 8, 0) ||
             (unsigned)src_y > FFMAX(s->v_edge_pos - (motion_y & 1) - 8, 0)) {
             s->vdsp.emulated_edge_mc(s->edge_emu_buffer, s->linesize, src,