libata: skip suppress reporting if ATA_EHI_QUIET

ATA_EHI_NO_AUTOPSY and ATA_EHI_QUIET are used during initial probing
to skip exception analysis and reporting.  Usually, there's nothing to
report but on some allowed but rare corner cases (e.g. phy status
changed interrupt when IRQ is enabled on frozen port - this happens if
IRQ pending status isn't cleared in the IRQ router or controller)
exception messages get printed.

Skip reporting if ATA_EHI_QUIET is set.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>