fix drivers/ata/sata_fsl.c double-decl

drivers/ata/sata_fsl.c: In function 'sata_fsl_fill_sg':
drivers/ata/sata_fsl.c:337: error: redeclaration of 'si' with no linkage
drivers/ata/sata_fsl.c:326: error: previous declaration of 'si' was here

Reported-by: Olof Johansson <olof@lixom.net>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>