LU-8824 nodemap: properly handle errors loading nodemap conf

LU-8824 nodemap: properly handle errors loading nodemap conf

Modifies mgc_process_recover_nodemap_log to properly handle errors
returned by nodemap_process_idx_pages. Previously, these errors were
ignored.

Signed-off-by: Kit Westneat <kit.westneat@gmail.com>
Change-Id: Icf0590eddf45d86a72623aeda863aee064993953
Reviewed-on: http://review.whamcloud.com/23778
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>