test: remove some unnecessary bash dependencies

/bin/bash is not so ubiquitous.

Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
packet lib: pep8 warning fix

run_tests.sh complained.

	ryu/lib/packet/icmp.py:102:15: E271 multiple spaces after keyword
		return  msg
		      ^

Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
dpset: fix join race

the datapath object should be added to the list in DPSet before
datapath_join event is fired.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>