virttest.utils_misc: Convert host_setup_flag into int

If host_setup_flag is set up in cfg files. Convert it to int in this
step. This can ignore the type error when use it for bit check.

Signed-off-by: Yiqiao Pu <ypu@redhat.com>
Merge pull request #832 from ypu/host_setup_flag

virttest.utils_misc: Convert host_setup_flag into int