common/rc: only force nfs4.2 non-default SEEK_HOLE behaviour

common/rc: only force nfs4.2 non-default SEEK_HOLE behaviour

Only NFSv4.2 supports non-defautl SEEK_HOLE behaviour. Thus default
SEEK_HOLE behaviour shall be allowed for NFSv4.0/4.1, or it will fail
generic/285, generic/448, generic/490 on NFSv4.0/4.1, complaining they
should support non-default SEEK_HOLE behaviour.

The *.full log is like:
	File system supports the default behavior.
	Default behavior is not allowed. Aborting.

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>