vcomp/lavc version: print ver from run-time linked

Do print the runtime lavc version instead the one from headers, that
may differ (minor and patch only).

Author: MartinPulec

src/video_compress/libavcodec.cpp

@@ -456,7 +456,10 @@ void usage(bool full) {
               << "' to display encoder specific options/examples; works\nfor "
                  "decoders as well (use the keyword \"enc[oder]\", anyways).\n";
         col() << "\n";
-        col() << "Libavcodec version (linked): " << SBOLD(LIBAVCODEC_IDENT) << "\n";
+        const unsigned lavc_ver = avcodec_version();
+        color_printf("Libavcodec version (linked): " TBOLD("%d.%d.%d") "\n",
+                     AV_VERSION_MAJOR(lavc_ver), AV_VERSION_MINOR(lavc_ver),
+                     AV_VERSION_MICRO(lavc_ver));
         const char *swscale = "no";
 #ifdef HAVE_SWSCALE
         swscale = "yes";