RPKI RTR: Wrong decoding of RPKI RTR End of Data PDU

The decoding of the End of Data PDU ignores the Serial Number, i.e., the last 32 bit of this PDU. Instead of that the current dissector implementation starts to decode a new RTR PDU.

Details of packet format see http://tools.ietf.org/html/rfc6810#section-5.8

Found by Matthias Wählisch

Bug: 10411
Change-Id: I8451b5fbda18a034022b97ff442ddb2a2dabed7b
Reviewed-on: https://code.wireshark.org/review/3832
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
(cherry picked from commit f44e082fa8403023425e27b28cb295f4e40e34e6)
Reviewed-on: https://code.wireshark.org/review/3834