[SCSI] target: remove EXTRA_CFLAGS

Add the current directory is superflous in general, and no includes in
drivers/scsi are needed either.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

drivers/target/Makefile

-EXTRA_CFLAGS += -I$(srctree)/drivers/target/ -I$(srctree)/drivers/scsi/
 
 target_core_mod-y		:= target_core_configfs.o \
 				   target_core_device.o \