hpsa: get rid of cmd_special_alloc and cmd_special_free

We have commands reserved for internal use.

This is laying the groundwork for removing the internal
queue of commands from the driver so that the locks that
protect that queue may be removed.

Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/hpsa.h

@@ -170,7 +170,7 @@ struct ctlr_info {
 	unsigned long transMethod;
 
 	/* cap concurrent passthrus at some reasonable maximum */
-#define HPSA_MAX_CONCURRENT_PASSTHRUS (20)
+#define HPSA_MAX_CONCURRENT_PASSTHRUS (10)
 	spinlock_t passthru_count_lock; /* protects passthru_count */
 	int passthru_count;