lm63: dev_warn -> dev_printk(KERN_DEBUG

Don't use dev_warn() to report every failed read/write attempt. Instead,
use dev_printk(KERN_DEBUG,...) to reduce clutter on the serial console
output.
Only use dev_warn() if we decide to give up after n retries.

Change-Id: I5d008288d6d999eeed05d406f1c0aa5bdc26ee4d
1 file changed