iscsi-target; Bump default CmdSN Depth to 64

This patch bumps the default TA_DEFAULT_CMDSN_DEPTH from 16 -> 64,
which is closer to a sane default for larger pipes @ 10 Gb/sec
with traditional iSCSI, or @ 40/56 Gb/sec Ethernet/Infiniband with
iSCSI Extentions for RDMA.

There is really no downside to increasing this default value for
1 Gb/sec.
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/iscsi/iscsi_target_core.h

@@ -49,7 +49,7 @@
 #define TA_NETIF_TIMEOUT_MAX		15
 #define TA_NETIF_TIMEOUT_MIN		2
 #define TA_GENERATE_NODE_ACLS		0
-#define TA_DEFAULT_CMDSN_DEPTH		16
+#define TA_DEFAULT_CMDSN_DEPTH		64
 #define TA_DEFAULT_CMDSN_DEPTH_MAX	512
 #define TA_DEFAULT_CMDSN_DEPTH_MIN	1
 #define TA_CACHE_DYNAMIC_ACLS		0