target: remove unused TARGET_CORE_CONFIG_ROOT define

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

include/target/target_core_configfs.h

 
-#define TARGET_CORE_CONFIG_ROOT	"/sys/kernel/config"
-
 #define TARGET_CORE_NAME_MAX_LEN	64
 #define TARGET_FABRIC_NAME_SIZE		32