LU-5988 obdclass: drop malloc fault and page accounting

LU-5988 obdclass: drop malloc fault and page accounting

Remove the OBD_ALLOC() memory allocation fault injection since this
is also possible with existing kernel mechanisms and it is no longer
useful to have Lustre-specific code to do this.

Remove the page allocation counters and OBD_PAGE_{ALLOC,FREE} helpers
that are almost entirely unused since the move to CLIO.

Update the max memory allocation counter on /proc read, so that it
doesn't show as lower than the current allocation, in case it hasn't
been updated since the previous ping.

Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: I024919d1e81730a9388e7999938a4cca1e1cab07
Reviewed-on: http://review.whamcloud.com/15110
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Niu Yawei <yawei.niu@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>