fix 'utils.libc_search' function bug

[rootklt]

execute 'find' in libc-database,output like this:
'ubuntu-xenial-amd64-libc6-i386 (id libc6-i386_2.23-0ubuntu10_amd64)'

utils.libc_search:
libc_name = '{}.so'.format(re.findall(r'\((.*?)\)',result[choice])[0])
the regex pattern will return:
'id libc6-i386_2.23-0ubuntu10_amd64'
join to libc-database path:
libc_path = os.path.join(DB, libc_name)
libc_path = 'libc-database-path/id libc6-i386_2.23-0ubuntu10_amd64'

it will issue 'no folder or file ERROR'

FIX:
libc_name = '{}.so'.format(re.findall(r'\(id (.*?)\)',result[choice])[0])