x86/CPU: extend is_forced_cpu_cap()'s "reach"

"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: 93401e28a8 ("x86: clear RDRAND CPUID bit on AMD family 15h/16h")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

xen/arch/x86/cpu/common.c

@@ -96,7 +96,7 @@ void __init setup_force_cpu_cap(unsigned int cap)
 
 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)