Commit df29d03f1d ("libxc/x86: avoid certain overflows in CPUID APIC ID
adjustments" introduced a one bit too narrow mask when checking whether
multiplying by 1 (in particular in leaf 1) would result in overflow.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>