[flang] Fix bug determining alternate return

[tskeith]

Summary

The arguments have been moved out of the analyzer so we can't get the
expected number there. Instead use the argument count from the newly
built callee.

flang/lib/Semantics/expression.cpp

void ExpressionAnalyzer::Analyze(const parser::CallStmt &callStmt) {
   if (!analyzer.fatalErrors()) {
     if (std::optional<CalleeAndArguments> callee{
             GetCalleeAndArguments(std::get<parser::ProcedureDesignator>(call.t),
                 analyzer.GetActuals(), true /* subroutine */)}) {
       ProcedureDesignator *proc{std::get_if<ProcedureDesignator>(&callee->u)};
       CHECK(proc);
       if (CheckCall(call.source, *proc, callee->arguments)) {
         bool hasAlternateReturns{
-            analyzer.GetActuals().size() < actualArgList.size()};
+            callee->arguments.size() < actualArgList.size()};
         callStmt.typedCall.reset(new ProcedureRef{std::move(*proc),
             std::move(callee->arguments), hasAlternateReturns});
       }
     }
   }
 }
 
 const Assignment *ExpressionAnalyzer::Analyze(const parser::AssignmentStmt &x) {