eth: Reset pack_seq even if the header is not marked as valid

Signed-off-by: Alex Forencich <alex@alexforencich.com>

src/eth/tb/baser.py

@@ -732,6 +732,8 @@ class BaseRSerdesSink:
 
                 if self.pack_seq < self.pack_cnt:
                     continue
+
+                self.pack_seq = 0
             else:
                 data = data_in
                 hdr = hdr_in