kvm-tools: fix wrong "./lkvm list -i"

because the program name is changed, "./lkvm list -i" can't work now.
This fix just remove the test:
1) this test is not reliable.
2) the target process can respond for "get_pid()", it must be
   kvm-tool. (at least it is more reliable)

Acked-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>