[PATCH] ata: libata-core: fix sloppy typing in ata_id_n_sectors()

[Sergey Shtylyov <s.shtylyov@omp.ru>]

The code multiplying the # of cylinders/heads/sectors in ata_id_n_sectors()
to get a disk capacity implicitly uses the *int* type for that calculation
and casting the result to 'u64' before returning ensues a sign extension.
Explicitly casting the 'u16' typed multipliers to 'u32' results in avoiding
a sign extension instruction and so in a more compact code...

Found by Linux Verification Center (linuxtesting.org) with the SVACE static
analysis tool.

Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>

---
This patch is against the 'for-next' branch of Damien's 'libata.git' repo.

 drivers/ata/libata-core.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

Index: libata/drivers/ata/libata-core.c
===================================================================
--- libata.orig/drivers/ata/libata-core.c
+++ libata/drivers/ata/libata-core.c
@@ -1107,11 +1107,13 @@ static u64 ata_id_n_sectors(const u16 *i
 			return ata_id_u32(id, ATA_ID_LBA_CAPACITY);
 	} else {
 		if (ata_id_current_chs_valid(id))
-			return id[ATA_ID_CUR_CYLS] * id[ATA_ID_CUR_HEADS] *
-			       id[ATA_ID_CUR_SECTORS];
+			return (u32)id[ATA_ID_CUR_CYLS] *
+			       (u32)id[ATA_ID_CUR_HEADS] *
+			       (u32)id[ATA_ID_CUR_SECTORS];
 		else
-			return id[ATA_ID_CYLS] * id[ATA_ID_HEADS] *
-			       id[ATA_ID_SECTORS];
+			return (u32)id[ATA_ID_CYLS] *
+			       (u32)id[ATA_ID_HEADS] *
+			       (u32)id[ATA_ID_SECTORS];
 	}
 }