agblklog could plausibly be 32, but that would overflow this shift.
Perform the shift as ULL and cast to u32 at the end instead.
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Acked-by: Jan Beulich <jbeulich@suse.com>