multiple users have attempted to run influxdb in a docker container
with a windows host and a volume mounted from windows. that causes
problems because it apparently uses samba/cifs which does not
support fsync on directories. this patchset will, if it receives an EINVAL
on directory fsync, as is what appears to happen on samba/cifs, then it
will ignore it. this should help.
fixes#9833.
fixes#9630.