x86/microcode: Remove unnecessary paravirt_enabled check

Commit:

  a18a0f68 ("x86, microcode: Don't initialize microcode code on paravirt")

added a paravirt test in microcode_init(), primarily to avoid making
mc_bp_resume()->load_ucode_ap()->check_loader_disabled_ap() calls
because on 32-bit kernels this callchain ends up using __pa_nodebug()
macro which is invalid for Xen PV guests.

A subsequent commit:

  fbae4ba8 ("x86, microcode: Reload microcode on resume")

eliminated this callchain thus making a18a0f68 unnecessary.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: david.vrabel@citrix.com
Cc: konrad.wilk@oracle.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1455612202-14414-2-git-send-email-bp@alien8.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/microcode/core.c

@@ -623,7 +623,7 @@ int __init microcode_init(void)
 	struct cpuinfo_x86 *c = &boot_cpu_data;
 	int error;
 
-	if (paravirt_enabled() || dis_ucode_ldr)
+	if (dis_ucode_ldr)
 		return -EINVAL;
 
 	if (c->x86_vendor == X86_VENDOR_INTEL)