event/dlb: fix header includes for musl

event/dlb: fix header includes for musl

The header file fcntl.h should not be included from sys/ directory
as done in dlb drivers, it is an error with musl libc.

Fixes: 19980083fd57 ("event/dlb: add eventdev probe")
Fixes: 5433956d5185 ("event/dlb2: add eventdev probe")
Cc: stable@dpdk.org
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Acked-by: David Marchand <david.marchand@redhat.com>
Acked-by: Timothy McDaniel <timothy.mcdaniel@intel.com>