target: improve Data-Out and NOP timeout error reporting

The following patchset converts existing Data-Out and NOP ping timeout messages from pr_debug() to pr_error(), to reflect the seriousness of unexpected connection termination events.

These events can be triggered using a couple of libiscsi client hacks:
https://github.com/ddiss/libiscsi/tree/hack-lio-trigger-dataout-timeout
https://github.com/ddiss/libiscsi/tree/hack-lio-trigger-nop-timeout

Cheers, David

--

 drivers/target/iscsi/iscsi_target_erl1.c | 21 ++++++++++++++++++---
 drivers/target/iscsi/iscsi_target_stat.c |  4 ++--
 drivers/target/iscsi/iscsi_target_util.c |  2 +-
 include/target/iscsi/iscsi_target_core.h |  6 +++---
 include/target/iscsi/iscsi_target_stat.h |  4 ++--
 5 files changed, 26 insertions(+), 11 deletions(-)