Add autoconf test for CAN.

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>
can: cleanup

* Add can/Makefile

* can/filter-tests/Makefile cleanup:
  - Intall the files into the expect points.

* run_ltp-can_tests.sh cleanup:
  - Use TCID, TST_TOTAL and TST_COUNT.
  - Use test.sh that some functions required.
  - Use tst_require_root and tst_resm.
  - Add setup and cleanup function.

* tst-filter.c and tst-rcv-own-msgs.c:
  - Use "tst_res_flags.h" to correctly return the value.
  - Some cleanup.

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>
Make can testes' name more saner

* Add can to scenario_groups/default.

* Add can_filter and can_rcv_own_msgs to network/.gitignore.

* Make the test's name more saner:
	tst-filter.c --> can_filter.c
	tst-rcv-own-msgs.c --> can_rcv_own_msgs.c
	run_ltp-can_tests.sh --> can_run_tests.sh

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>