staging/lustre/llite: hold inode mutex around ll_setattr_raw()

ll_setattr_raw() expects to be called with the inode mutex held so do
when calling it from ll_hsm_import().

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Reviewed-on: http://review.whamcloud.com/11349
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5456


Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Faccini Bruno <bruno.faccini@intel.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>