KVM: SVM: Open code handling of unexpected exits in svm_invoke_exit_handler()

Fold svm_check_exit_valid() and svm_handle_invalid_exit() into their sole
caller, svm_invoke_exit_handler(), as having tiny single-use helpers makes
the code unncessarily difficult to follow.  This will also allow for
additional cleanups in svm_invoke_exit_handler().

No functional change intended.

Suggested-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Link: https://patch.msgid.link/20251230211347.4099600-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

arch/x86/kvm/svm/svm.c

@@ -3467,23 +3467,13 @@ static void dump_vmcb(struct kvm_vcpu *vcpu)
 		sev_free_decrypted_vmsa(vcpu, save);
 }
 
-static bool svm_check_exit_valid(u64 exit_code)
-{
-	return (exit_code < ARRAY_SIZE(svm_exit_handlers) &&
-		svm_exit_handlers[exit_code]);
-}
-
-static int svm_handle_invalid_exit(struct kvm_vcpu *vcpu, u64 exit_code)
-{
-	dump_vmcb(vcpu);
-	kvm_prepare_unexpected_reason_exit(vcpu, exit_code);
-	return 0;
-}
-
 int svm_invoke_exit_handler(struct kvm_vcpu *vcpu, u64 exit_code)
 {
-	if (!svm_check_exit_valid(exit_code))
-		return svm_handle_invalid_exit(vcpu, exit_code);
+	if (exit_code >= ARRAY_SIZE(svm_exit_handlers))
+		goto unexpected_vmexit;
+
+	if (!svm_exit_handlers[exit_code])
+		goto unexpected_vmexit;
 
 #ifdef CONFIG_MITIGATION_RETPOLINE
 	if (exit_code == SVM_EXIT_MSR)
@@ -3502,6 +3492,11 @@ int svm_invoke_exit_handler(struct kvm_vcpu *vcpu, u64 exit_code)
 #endif
 #endif
 	return svm_exit_handlers[exit_code](vcpu);
+
+unexpected_vmexit:
+	dump_vmcb(vcpu);
+	kvm_prepare_unexpected_reason_exit(vcpu, exit_code);
+	return 0;
 }
 
 static void svm_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason,