[MLIR][NFC] Fix misleading diagnostic error + clang-tidy fix

[bondhugula]

Summary

Fix misleading diagnostic error in affine.yield verifier + a clang-tidy fix.

[rriddle]

Do we not have a test for this?

[bondhugula]

In D85587#2204853, @rriddle wrote:

Do we not have a test for this?

Yes, we unfortunately don't have one for this. I thought of adding one but found it wasn't that useful. Can add it if you think otherwise.

[flaub]

LGTM, thanks!

mlir/lib/Dialect/Affine/IR/AffineOps.cpp

for (const auto &result : stepsMap.getResults()) {
                                 "steps must be constant integers");
       steps.push_back(constExpr.getValue());
     }
     result.addAttribute(AffineParallelOp::getStepsAttrName(),
                         builder.getI64ArrayAttr(steps));
   }
 
   // Parse optional clause of the form: `reduce ("addf", "maxf")`, where the
-  // quoted strings a member of the enum AtomicRMWKind.  
+  // quoted strings a member of the enum AtomicRMWKind.
   SmallVector<Attribute, 4> reductions;
   if (succeeded(parser.parseOptionalKeyword("reduce"))) {
     if (parser.parseLParen())
       return failure();
     do {
       // Parse a single quoted string via the attribute parsing, and then
       // verify it is a member of the enum and convert to it's integer
       // representation.
static ParseResult parseAffineParallelOp(OpAsmParser &parser,
   return success();
 }
 
 //===----------------------------------------------------------------------===//
 // AffineYieldOp
 //===----------------------------------------------------------------------===//
 
 static LogicalResult verify(AffineYieldOp op) {
-  auto parentOp = op.getParentOp();
+  auto *parentOp = op.getParentOp();
   auto results = parentOp->getResults();
   auto operands = op.getOperands();
 
   if (!isa<AffineParallelOp, AffineIfOp, AffineForOp>(parentOp))
-    return op.emitOpError()
-           << "affine.terminate only terminates If, For or Parallel regions";
+    return op.emitOpError() << "only terminates affine.if/for/parallel regions";
   if (parentOp->getNumResults() != op.getNumOperands())
     return op.emitOpError() << "parent of yield must have same number of "
                                "results as the yield operands";
   for (auto it : llvm::zip(results, operands)) {
     if (std::get<0>(it).getType() != std::get<1>(it).getType())
       return op.emitOpError()
              << "types mismatch between yield op and its parent";
   }