LU-9183 libcfs: handle get_user_pages() with gup_flags

LU-9183 libcfs: handle get_user_pages() with gup_flags

In commit c8fe4609827aedc9c4b45de80e7cdc8ccfa8541b the arguments
write/force for get_user_pages() were replaced with gup_flags.

Change-Id: I64b3e69ee736d1f3be48f2c4c8fe1af1dc14e857
Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-on: https://review.whamcloud.com/25817
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>