hpsa: remove dev_dbg() calls from hot paths

They are not completely free of cost when disabled and
when enabled emitting debug output for every command
submitted produces far too much output to be useful.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: Mike Miller <michael.miller@canonical.com>
Reviewed-by: Webb Scales <webb.scales@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>