osp_xattr_get() fails due to hardcoded
reply size limitation.

With large_xattr enabled ddp_max_ea_size can be
almost 1MB and out_handles fails to send such big
reply.

Limit maximum ACL buffer size by XATTR_SIZE_MAX.
Limit ddp_max_ea_size to fit resulting reply
request into LNET_MTU.

Cray-bug-id: MRP-4724
Change-Id: I6405330605809911c3f814fe5cb9d476d7ac40ed
Signed-off-by: Andriy Skulysh <c17819@cray.com>
Reviewed-on: https://review.whamcloud.com/31088


Reviewed-by: Alexandr Boyko <c17825@cray.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andrew Perepechko <c17827@cray.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>