scsi: target: drop unnecessary get_fabric_name() accessor from fabric_ops

All fabrics return a const string. In all cases *except* iSCSI the
get_fabric_name() string matches fabric_ops.name.

Both fabric_ops.get_fabric_name() and fabric_ops.name are user-facing, with
the former being used for PR/ALUA state and the latter for ConfigFS
(config/target/$name), so we unfortunately need to keep both strings around
for now.  Replace the useless .get_fabric_name() accessor function with a
const string fabric_name member variable.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

include/target/target_core_fabric.h

@@ -9,6 +9,11 @@
 struct target_core_fabric_ops {
 	struct module *module;
 	const char *name;
+	/*
+	 * fabric_name is used for the ALUA state path and is stored on disk
+	 * with PR state.
+	 */
+	const char *fabric_name;
 	size_t node_acl_size;
 	/*
 	 * Limits number of scatterlist entries per SCF_SCSI_DATA_CDB payload.
@@ -23,7 +28,6 @@ struct target_core_fabric_ops {
 	 * XXX: Currently assumes single PAGE_SIZE per scatterlist entry
 	 */
 	u32 max_data_sg_nents;
-	char *(*get_fabric_name)(void);
 	char *(*tpg_get_wwn)(struct se_portal_group *);
 	u16 (*tpg_get_tag)(struct se_portal_group *);
 	u32 (*tpg_get_default_depth)(struct se_portal_group *);