ndb - fixed for BUG#19896 Last_Errno: 4294967295, Error in Write_rows event: (error number 4 billion ?)

fixed to use int instead of uint32 type to return last_slave_errno.


sql/log_event.cc:
  don't set -1 to last_slave_errno.
sql/protocol.h:
  added function store(int from) to return last_slave_errno.
sql/slave.cc:
  should use int instead of uint32 type to return last_slave_errno.