Fix scsi_debug build error:

drivers/built-in.o: In function `resp_read':
scsi_debug.c:(.text+0x21379a): undefined reference to `crc_t10dif'
drivers/built-in.o: In function `resp_write':
scsi_debug.c:(.text+0x213fca): undefined reference to `crc_t10dif'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>