xfs: introduce xfs_validate_stripe_geometry()

Introduce a common helper to consolidate stripe validation process.
Also make kernel code xfs_validate_sb_common() use it first.

Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>