LU-690 test: wait_osc_import_state() fixes

LU-690 test: wait_osc_import_state() fixes

b=24498 wait_osc_import_state() fixes

i=Vladimir.Saveliev

-- increase maxtime to wait the timeout of 1st request;
   take into account at_min value;
-- cleanup wait_osc_import_state() to use _wait_import_state();
-- ost-pools test_1 fix: use local var instead of global NAME

Signed-off-by: Elena Gryaznova <elena.gryaznova@oracle.com>
Signed-off-by: Yu Jian <yujian@whamcloud.com>
Change-Id: I36b163a291d783b1d772f05898ccee783d815298
Reviewed-on: http://review.whamcloud.com/1499
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Minh Diep <mdiep@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>