KVM: X86: Rename variable smap to not_smap in permission_fault()

Comments above the variable says the bit is set when SMAP is overridden
or the same meaning in update_permission_bitmask(): it is not subjected
to SMAP restriction.

Renaming it to reflect the negative implication and make the code better
readability.
Signed-off-by: NLai Jiangshan <jiangshan.ljs@antgroup.com>
Message-Id: <20220311070346.45023-4-jiangshanlai@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu.h

@@ -234,9 +234,9 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 	 * but it will be one in index if SMAP checks are being overridden.
 	 * It is important to keep this branchless.
 	 */
-	unsigned long smap = (cpl - 3) & (rflags & X86_EFLAGS_AC);
+	unsigned long not_smap = (cpl - 3) & (rflags & X86_EFLAGS_AC);
 	int index = (pfec >> 1) +
-		    (smap >> (X86_EFLAGS_AC_BIT - PFERR_RSVD_BIT + 1));
+		    (not_smap >> (X86_EFLAGS_AC_BIT - PFERR_RSVD_BIT + 1));
 	bool fault = (mmu->permissions[index] >> pte_access) & 1;
 	u32 errcode = PFERR_PRESENT_MASK;