drivers/leds/leds-tca6507.c: remove obsolete cleanup for clientdata

A few new i2c-drivers came into the kernel which clear the
clientdata-pointer on exit or error.  This is obsolete meanwhile, the
core will do it.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: NeilBrown <neilb@suse.de>
Cc: Richard Purdie <rpurdie@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>