MFC r298698:

MFC r298698:
geom: unsign some types to match their definitions and avoid overflows.

In struct:gctl_req, nargs is unsigned.

In mirror:
g_mirror_syncreqs is unsigned.

In raid:
in struct:g_raid_volume, v_disks_count is unsigned.

In virstor:
in struct:g_virstor_softc, n_components is unsigned.

git-svn-id: svn://svn.freebsd.org/base/stable/10@299397 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f