[PATCH] libata.h needs scatterlist.h

[PATCH] libata.h needs scatterlist.h

From: Andrew Morton <akpm@osdl.org>

s390:

In file included from drivers/scsi/libata-bmdma.c:39:                           include/linux/libata.h:391: error: field 'sgent' has incomplete type
include/linux/libata.h:392: error: field 'pad_sgent' has incomplete type
include/linux/libata.h: In function 'ata_sg_is_last':                           include/linux/libata.h:849: error: arithmetic on pointer to an incomplete type
include/linux/libata.h:849: error: arithmetic on pointer to an incomplete type
include/linux/libata.h: In function 'ata_qc_next_sg':
include/linux/libata.h:869: error: increment of pointer to unknown structure
include/linux/libata.h:869: error: arithmetic on pointer to an incomplete type
include/linux/libata.h:869: error: arithmetic on pointer to an incomplete type
include/linux/libata.h:869: error: arithmetic on pointer to an incomplete type

Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>