Crypto: Fix bug in MacOperationNode constructor with detecting if the operation is also used for signatures.

Author: bdrodes

shared/quantum/codeql/quantum/experimental/Model.qll

@@ -1597,8 +1597,8 @@ module CryptographyBase<LocationSig Location, InputSig<Location> Input> {
   final class MacOperationNode extends SignatureOrMacOperationNode {
     MacOperationNode() {
       this.getKeyOperationSubtype() = TMacMode() and
-      // If the type could be a mac, then we will not consider it a mac operation exclusively.
-      not exists(KeyOperationSubtype t | t = this.getKeyOperationSubtype() and t = TMacMode())
+      // If the type could be a signature, then we will not consider it a mac operation exclusively.
+      not exists(KeyOperationSubtype t | t = this.getKeyOperationSubtype() and t = TSignMode())
     }
 
     final override string getInternalType() { result = "MACOperation" }