x86/speculation: Simplify sysfs report of VMX L1TF vulnerability

x86/speculation: Simplify sysfs report of VMX L1TF vulnerability

Three changes to the content of the sysfs file:

 - If EPT is disabled, L1TF cannot be exploited even across threads on the
   same core, and SMT is irrelevant.

 - If mitigation is completely disabled, and SMT is enabled, print "vulnerable"
   instead of "vulnerable, SMT vulnerable"

 - Reorder the two parts so that the main vulnerability state comes first
   and the detail on SMT is second.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Orabug: 28220674
CVE: CVE-2018-3620

(cherry picked from commit ea156d192f5257a5bf393d33910d3b481bf8a401)

Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Conflicts:
	arch/x86/kernel/cpu/bugs.c
Different filename: bugs_64.c