libata: report link resume failure as KERN_WARNING instead of ERR
Link resume failure in itself isn't an error condition and may happen
regularly depending on hardware configuration. Reporting it as
KERN_ERR makes the condition unnecessarily prominent (e.g. reported
during boot). Use KERN_WARNING instead.
Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: David Shaw <dshaw@jabberwocky.com> Signed-off-by: Jeff Garzik <jgarzik@pobox.com>