MFH: r544794
devel/sigar: build after filedesc struct change
In base revision r363214[1] we dropped the fd_lastfile field of the
filedesc struct. This breaks devel/sigar.
The applied solution was proposed by mjg@ in this[2] mail thread.
[1] https://svnweb.freebsd.org/changeset/base/363214
[2] https://lists.freebsd.org/pipermail/freebsd-ports/2020-August/119093.html
PR: 248460
Submitted by: ronald-lists@klop.ws
Approved by: ports-secteam (blanket, build fix)