Since there is already a generic function strstarts() that check if a
string starts with a given prefix, cleanup str_starts_with().

Signed-off-by: Wei Li <liwei391@huawei.com>
Acked-by: Peter Kästle <peter@piie.net>
Link: https://lore.kernel.org/r/20220326020249.3266561-1-liwei391@huawei.com


Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>