Sector offset can not be negative, make it unsigned.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/block/fdc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/block/fdc.c b/hw/block/fdc.c
index 2cec7568c1..c91ed7ee2d 100644
--- a/hw/block/fdc.c
+++ b/hw/block/fdc.c
@@ -259,7 +259,7 @@ static uint32_t fd_sector(FDrive *drv)
 }
 
 /* Returns current position, in bytes, for given drive */
-static int fd_offset(FDrive *drv)
+static uint64_t fd_offset(FDrive *drv)
 {
     g_assert(fd_sector(drv) < INT_MAX >> BDRV_SECTOR_BITS);
     return fd_sector(drv) << BDRV_SECTOR_BITS;
-- 
2.21.3