nvme: remove the udev optional dependency

Upstream removed the udev dependent code in commit 4cbe5888f4bc (nvme-cli:
fabrics: remove libudev dependency).

Cc: Mamatha Inamdar <mamatha4@linux.vnet.ibm.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>