[PATCH] lm3697: Rename struct into more appropiate name

[ultracoolguy]

 Subject says it all. This rename was briefly discussed in this other patch: https://www.spinics.net/lists/linux-leds/msg16865.html (I don't know another way to link to emails, so I'll just use this archive).

Feel free to suggest another name for the commit; that was just the better name I could come up with :/ .