xfs: create internal eofblocks structure with kuid_t types

Have eofblocks ioctl convert uid_t to kuid_t into internal structure.
Update internal filter matching to compare ids with kuid_t types.

Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
Signed-off-by: Ben Myers <bpm@sgi.com>