staging: lustre: llite: Report first encountered error

Failures in ll_ioc_copy_{start,end} are reported to coordinator.
The return code delivered to the caller should indicate what this
error was, not whether coordinator was successfully notified.

Signed-off-by: Henri Doreau <henri.doreau@cea.fr>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5683
Reviewed-on: http://review.whamcloud.com/14335


Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>