Reuse existing macro to simplify the code and improve readability.

Cc: Joerg Roedel <jroedel@suse.de>
Cc: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>