base/nebmods: Add mode argument to open()

This patch fixes an attribute error during compilation due to glibc
enforcing the requirement that the mode argument to open() is supplied
when O_CREAT is set in flags.

Signed-off-by: Andreas Ericsson <ae@op5.se>
base/checks: Add latency data to check_result struct

This trivial patches fixes an issue where service check latency is
always reset to zero after scheduled checks.

Signed-off-by: Andreas Ericsson <ae@op5.se>