tmem: shared ephemeral (SE) pool (clustering) fixes

tmem: shared ephemeral (SE) pool (clustering) fixes

Tmem can share clean page cache pages for Linux domains
in a virtual cluster (currently only the ocfs2 filesystem
has a patch on the Linux side).  So when one domain
"puts" (evicts) a page, any domain in the cluster can
"get" it, thus saving disk reads.  This functionality
is already present; these are only bug fixes.

- fix bugs when an SE pool is destroyed
- fixes in parsing tool for xm tmem-list output for SE pools
- incorrect locking in one case for destroying an SE pool
- clearer verbosity for transfer when an SE pool is destroyed
- minor cleanup: merge routines that are mostly duplicate

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>