warning: `i2c_readbytes' defined but not used

This code will either be re-enabled or deleted in a future patch.
Signed-off-by: Michael Krufky <mkrufky@m1k.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>