mxfdec: Check eof_reached in mxf_read_local_tags()

This fixes an infinite loop with zzuf2.mxf.
Signed-off-by: Diego Biurrun <diego@biurrun.de>

libavformat/mxfdec.c

@@ -1471,7 +1471,7 @@ static int mxf_read_local_tags(MXFContext *mxf, KLVPacket *klv, MXFMetadataReadF
 
     if (!ctx)
         return AVERROR(ENOMEM);
-    while (avio_tell(pb) + 4 < klv_end) {
+    while (avio_tell(pb) + 4 < klv_end && !pb->eof_reached) {
         int ret;
         int tag = avio_rb16(pb);
         int size = avio_rb16(pb); /* KLV specified by 0x53 */