kpartx: remove unused "-n" code
kpartx: remove unused "-n" code

Signed-Off-By: Guido Guenther <7ebf60a2ee90c1ac7f28776faba2e1a6e374ba74@sigxcpu.org>

grzn/multipath-tools-explained,vijaychauhan/multipath-tools,unakatsuo/multipath-tools,gebi/multipath-tools,unakatsuo/multipath-tools,vijaychauhan/multipath-tools,unakatsuo/multipath-tools,grzn/multipath-tools-explained