Update python/ql/src/Functions/SignatureOverriddenMethod.ql

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: joefarebrother

python/ql/src/Functions/SignatureOverriddenMethod.ql

@@ -202,7 +202,7 @@ Call chooseASignatureMismatchWitness(Function base, Function sub) {
       c = getASignatureMismatchWitness(base, sub) and
       c.getLocation().getFile() = base.getLocation().getFile()
     ) and
-    result = chooseASignatureMismatchWitnessInFile(base, sub, base.getLocation().getFile())
+    result = chooseASignatureMismatchWitnessInFile(base, sub, sub.getLocation().getFile())
     or
     not exists(Call c |
       c = getASignatureMismatchWitness(base, sub) and