LU-4413 osp: move seq allocation out of osp_import_event

LU-4413 osp: move seq allocation out of osp_import_event

Because seq allocation(osp_init_pre_fid) might be stuck
during RPC, move it out of osp_import_event, which is
inside ptlrpcd_rcv. Otherwise, some other import RPCs(like
connect req)might be blocked in ptlrpcd_rcv.

Lustre-commit: 9b643f4f54c3e9e0c07c2211904a72ad9c4f823f
Lustre-change: http://review.whamcloud.com/8997

Signed-off-by: wang di <di.wang@intel.com>
Signed-off-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Change-Id: Ia41487d7859ec2cf8f0033dd97c7df98a18dcded
Reviewed-on: http://review.whamcloud.com/9875
Tested-by: Jenkins
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>