monitor: code move for parse_cmdline()

help_cmd() need this function later, so move it. get_str() is called by
parse_cmdline() so it is moved also. Some code style error reported by
check script, is also fixed.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
