trace: Avoid propagating unintended sign extension

The alternative would be to add casts to unsigned types in the
preceding statements (pretty much everywhere), so this seems like
the easier approach.

Signed-off-by: Patrick Georgi <[email protected]>
Change-Id: I1dba945ce86fc6a080725fd2f913abbbbc10191e
Reviewed-on: https://review.coreboot.org/c/em100/+/58427
Tested-by: build bot (Jenkins) <[email protected]>
Reviewed-by: Stefan Reinauer <[email protected]>
1 file changed