Revert "KVM: x86: Increase the number of fixed MTRR regs to 10"

This reverts commit 682367c4,
which causes 32-bit SMP Windows 7 guests to panic.

SeaBIOS has a limit on the number of MTRRs that it can handle,
and this patch exceeded the limit.  Better revert it.
Thanks to Nadav Amit for debugging the cause.

Cc: stable@nongnu.org
Reported-by: NWanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -95,7 +95,7 @@ static inline gfn_t gfn_to_index(gfn_t gfn, gfn_t base_gfn, int level)
 #define KVM_REFILL_PAGES 25
 #define KVM_MAX_CPUID_ENTRIES 80
 #define KVM_NR_FIXED_MTRR_REGION 88
-#define KVM_NR_VAR_MTRR 10
+#define KVM_NR_VAR_MTRR 8
 
 #define ASYNC_PF_PER_VCPU 64