test: clean up pages immediately after restore

We see big load-avarage for the CRIU-iter job, because the host is
writing images for the maps04 test. If we will remove images after retore,
they will live in a page cache. Curretly we collect images for three
iterations and their size is too big to live in a cache.

[root@jenkins workspace]# time bash test/zdtm.sh  -i 3 ns/static/maps04
real	2m23.765s
user	0m0.719s
sys	0m4.006s
[root@jenkins workspace]# time bash test/zdtm.sh -C -i 3 ns/static/maps04
real	1m34.884s
user	0m0.200s
sys	0m4.191s
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm.sh

@@ -762,6 +762,7 @@ EOF
 				diff_fds $ddump/dump.fd $ddump/restore.fd || return 2
 				diff_maps $ddump/dump.maps $ddump/restore.maps || return 2
 			}
+			[ "$CLEANUP" -ne 0 ] && rm -f --one-file-system $ddump/pages-*.img
 		fi
 
 	done