[lib] remove spurious and obsolete kdev_t.h include in directio checker
[lib] remove spurious and obsolete kdev_t.h include in directio checker

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