media: saa7134-go7007: get rid of to_state() function
This is just an alias for container_of() and it is used only
on a commented code. The commented code actually is an issue that
require fixes, so, move the container_of() call to the commented
code, and drop the unused function.
This way, a fix for the function could be added later without
needing to re-add to_state() function.