x86: Use common variable range MTRR counts

We currently define the number of variable range MTRR registers as 8
in the CPUX86State structure and vmstate, but use MSR_MTRRcap_VCNT
(also 8) to report to guests the number available.  Change this to
use MSR_MTRRcap_VCNT consistently.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Reviewed-by: NLaszlo Ersek <lersek@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

target-i386/cpu.h

@@ -930,7 +930,7 @@ typedef struct CPUX86State {
     /* MTRRs */
     uint64_t mtrr_fixed[11];
     uint64_t mtrr_deftype;
-    MTRRVar mtrr_var[8];
+    MTRRVar mtrr_var[MSR_MTRRcap_VCNT];
 
     /* For KVM */
     uint32_t mp_state;

target-i386/machine.c

@@ -677,7 +677,7 @@ VMStateDescription vmstate_x86_cpu = {
         /* MTRRs */
         VMSTATE_UINT64_ARRAY_V(env.mtrr_fixed, X86CPU, 11, 8),
         VMSTATE_UINT64_V(env.mtrr_deftype, X86CPU, 8),
-        VMSTATE_MTRR_VARS(env.mtrr_var, X86CPU, 8, 8),
+        VMSTATE_MTRR_VARS(env.mtrr_var, X86CPU, MSR_MTRRcap_VCNT, 8),
         /* KVM-related states */
         VMSTATE_INT32_V(env.interrupt_injected, X86CPU, 9),
         VMSTATE_UINT32_V(env.mp_state, X86CPU, 9),