MFH: r538811

databases/rrdtool: Fix resize on ZFS

Add an upstream patch that fixes resize on ZFS. Since ZFS does not support
posix_fallocate(), returning EINVAL, the patch simply ignores this error
from posix_fallocate().

PR: 245898
Reported by: Tomohiro Hosaka

Approved by: ports-secteam (joenum)