[SCSI] libiscsi: replace scsi_debug logging with session/conn logging

This makes the logging a compile time option and replaces
the scsi_debug macro with session and connection ones
that print out a driver model id prefix.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

include/scsi/libiscsi.h

@@ -45,13 +45,6 @@ struct iscsi_session;
 struct iscsi_nopin;
 struct device;
 
-/* #define DEBUG_SCSI */
-#ifdef DEBUG_SCSI
-#define debug_scsi(fmt...) printk(KERN_INFO "iscsi: " fmt)
-#else
-#define debug_scsi(fmt...)
-#endif
-
 #define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
 #define ISCSI_MGMT_CMDS_MAX	15