[SCSI] target: Minor sparse warning fixes and annotations

This patch addresses the majority of sparse warnings and adds
proper locking annotations.  It also fixes the dubious one-bit signed
bitfield, for which the signed one-bit types can be 0 or -1 which can
cause a problem if someone ever checks if (foo->lu_gp_assoc == 1).
The current code is fine because everyone just checks zero vs non-zero.
But Sparse complains about it so lets change it.  The warnings look like
this:

include/target/target_core_base.h:228:26: error: dubious one-bit signed bitfield

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Fubo Chen <fubo.chen@gmail.com>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 51fd309..7ff6a35 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -441,6 +441,7 @@
 	struct pscsi_dev_virt *pdv,
 	struct se_subsystem_dev *se_dev,
 	struct se_hba *hba)
+	__releases(sh->host_lock)
 {
 	struct se_device *dev;
 	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
@@ -488,6 +489,7 @@
 	struct pscsi_dev_virt *pdv,
 	struct se_subsystem_dev *se_dev,
 	struct se_hba *hba)
+	__releases(sh->host_lock)
 {
 	struct se_device *dev;
 	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
@@ -522,6 +524,7 @@
 	struct pscsi_dev_virt *pdv,
 	struct se_subsystem_dev *se_dev,
 	struct se_hba *hba)
+	__releases(sh->host_lock)
 {
 	struct se_device *dev;
 	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;