tests/lib/coreboot_table-test.c: Use ALIGN_UP macro

Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Change-Id: Ie0d4788c0a4ffee2f16bcf05e3454dbaeaa1606b
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67518
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jakub Czapiga <jacz@semihalf.com>

tests/lib/coreboot_table-test.c

@@ -20,8 +20,7 @@ static struct lb_header *lb_table_init(unsigned long addr)
 	struct lb_header *header;
 
 	/* 16 byte align the address */
-	addr += 15;
-	addr &= ~15;
+	addr = ALIGN_UP(addr, 16);
 
 	header = (void *)addr;
 	header->signature[0] = 'L';