As with previous patches, unify functions v9fs_tversion() and do_version()
into a single function v9fs_tversion() by using a declarative function
arguments approach.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <2d253491aaffd267ec295f056dda47456692cd0c.1664917004.git.qemu_oss@crudebyte.com>