Add debug log entries for failed receive records

Log contents of a receive record if an error occurs while writing
it out to the pool. This may help determine the cause when backup
streams are rejected as invalid.

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes #6465