lockfile: wait using sleep_millisec() instead of select()
Use the new function sleep_millisec() to delay execution for a short
time. This avoids the invocation of select() with just a timeout, but
no file descriptors. Such a use of select() is quit with EINVAL on
Windows, leading to no delay at all.
Signed-off-by: Johannes Sixt <j6t@kdbg.org> Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>