Remove useless if(), leftover from the vhook removal.

Originally committed as revision 19070 to svn://svn.ffmpeg.org/ffmpeg/trunk

ffmpeg.c

@@ -760,7 +760,6 @@ static void pre_process_video_frame(AVInputStream *ist, AVPicture *picture, void
         picture2 = &picture_tmp;
         avpicture_fill(picture2, buf, dec->pix_fmt, dec->width, dec->height);
 
-        if (do_deinterlace){
             if(avpicture_deinterlace(picture2, picture,
                                      dec->pix_fmt, dec->width, dec->height) < 0) {
                 /* if error, do not deinterlace */
@@ -769,9 +768,6 @@ static void pre_process_video_frame(AVInputStream *ist, AVPicture *picture, void
                 buf = NULL;
                 picture2 = picture;
             }
-        } else {
-            av_picture_copy(picture2, picture, dec->pix_fmt, dec->width, dec->height);
-        }
     } else {
         picture2 = picture;
     }