KVM: SEV: Fix typo in and tweak name of cmd_allowed_from_miror()

Rename cmd_allowed_from_miror() to is_cmd_allowed_from_mirror(), fixing
a typo and making it obvious that the result is a boolean where
false means "not allowed".

No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/sev.c

@@ -1509,7 +1509,7 @@ static int sev_receive_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	return sev_issue_cmd(kvm, SEV_CMD_RECEIVE_FINISH, &data, &argp->error);
 }
 
-static bool cmd_allowed_from_miror(u32 cmd_id)
+static bool is_cmd_allowed_from_mirror(u32 cmd_id)
 {
 	/*
 	 * Allow mirrors VM to call KVM_SEV_LAUNCH_UPDATE_VMSA to enable SEV-ES
@@ -1541,7 +1541,7 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
 
 	/* Only the enc_context_owner handles some memory enc operations. */
 	if (is_mirroring_enc_context(kvm) &&
-	    !cmd_allowed_from_miror(sev_cmd.id)) {
+	    !is_cmd_allowed_from_mirror(sev_cmd.id)) {
 		r = -EINVAL;
 		goto out;
 	}