misc: convert xfrog_bulkstat functions to have v5 semantics

misc: convert xfrog_bulkstat functions to have v5 semantics

Convert xfrog_bulkstat() and xfrog_bulkstat_single() to take arguments
using v5 bulkstat semantics and return bulkstat information in v5
structures.  If the v5 ioctl is not available, the xfrog wrapper should
use the v1 ioctl to emulate v5 behaviors.  Add flags to the xfs_fd
structure to constrain emulation for debugging purposes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>