"cpuid=no-rdrand" cannot actually be used to suppress the respective
boot warning on certain AMD hardware. That's because cleared_caps[] are
only applied after the ->c_init() hooks ran, i.e. cpu_has() still
returns true in init_amd().

Fixes: 93401e28a84b ("x86: clear RDRAND CPUID bit on AMD family 15h/16h")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
TBD: It's not clear whether doing it this way is actually a good idea;
     it may need to be two of the three call sites to be amended by a
     new is_cleared_cpu_cap().

Also relevant to "x86/AMD: disable RDSEED on Fam17 model 47 stepping 0".

--- a/xen/arch/x86/cpu/common.c
+++ b/xen/arch/x86/cpu/common.c
@@ -108,7 +108,7 @@ void __init setup_force_cpu_cap(unsigned
 
 bool __init is_forced_cpu_cap(unsigned int cap)
 {
-	return test_bit(cap, forced_caps);
+	return test_bit(cap, forced_caps) || test_bit(cap, cleared_caps);
 }
 
 static void cf_check default_init(struct cpuinfo_x86 * c)