media: imon: drop redundant device references

media: imon: drop redundant device references

Driver core holds a reference to the USB interface and its parent USB
device while the interface is bound to a driver and there is no need to
take additional references unless the structures are needed after
disconnect.

Drop the redundant device references to reduce cargo culting, make it
easier to spot drivers where extra references are needed, and reduce the
risk of memory leaks when drivers fail to release them.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>