LU-673 llite: Add some metadata stats, fix some file stats.

LU-673 llite: Add some metadata stats, fix some file stats.

Add LPROC_LL_CREATE, LPROC_LL_LINK, LPROC_LL_UNLINK, LPROC_LL_SYMLINK,
LPROC_LL_MKDIR, LPROC_LL_RMDIR, LPROC_LL_MKNOD, and LPROC_LL_RENAME
for successful calls to the corresponding directory inode operations.

Add LPROC_LL_READDIR for successful calls to ll_readdir().

Tally LPROC_LL_OPEN if and only if the call succeeds.  Under the
previous behavior, opens of a file that was already open locally with
the same flags were not tallied.

Do not tally LPROC_LL_SETATTR when the setattr is from truncate() or
truncate from open().

Tally LPROC_LL_TRUNC when appropriate in ll_setattr_raw(), but remove
tallies in ll_truncate() and vvp_io_init().  Under the previous
behavior, a single call to truncate() caused LPROC_LL_TRUNC to be
tallied 3 times (and similarly for truncate from open()).

Remove the unused stats LPROC_LL_WB_WRITEPAGE, LPROC_LL_WB_PRESSURE,
LPROC_LL_WB_OK, LPROC_LL_WB_FAIL, LPROC_LL_LOCKLESS_TRUNC,
LPROC_LL_DIRECT_READ, LPROC_LL_DIRECT_WRITE, LPROC_LL_LOCKLESS_READ,
and LPROC_LL_LOCKLESS_WRITE.

Change-Id: Id286a6eb986088ea109da2e6c6e31b9d21a34562
Signed-off-by: John L. Hammond <jhammond@tacc.utexas.edu>
Reviewed-on: http://review.whamcloud.com/1360
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Fan Yong <yong.fan@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>