root-disk implemented currently had issues where root
disk partitions getting modified might race and provide
incorrect results, to avoid this lets rely again back on
DeviceID and match it instead.
In-case of containers `/data` is one such extra entity that
needs to be verified for root disk, due to how 'overlay'
filesystem works and the 'overlay' presents a completely
different 'device' id - using `/data` as another entity
for fallback helps because our containers describe 'VOLUME'
parameter that allows containers to automatically have a
virtual `/data` that points to the container root path this
can either be at `/` or `/var/lib/` (on different partition)
till now we used to match the inode number of the root
drive and the drive path minio would use, if they match
we knew that its a root disk.
this may not be true in all situations such as running
inside a container environment where the container might
be mounted from a different partition altogether, root
disk detection might fail.
Harshavardhana