[MLIR] Apply clang-tidy fixes for llvm-qualified-auto in LoopInvariantCodeMotionUtils.cpp (NFC)

Author: joker-eph

mlir/lib/Transforms/Utils/LoopInvariantCodeMotionUtils.cpp

@@ -324,7 +324,7 @@ static LoopLikeOpInterface hoistSubsetAtIterArg(RewriterBase &rewriter,
                                                 LoopLikeOpInterface loopLike,
                                                 BlockArgument iterArg) {
   assert(iterArg.getOwner()->getParentOp() == loopLike && "invalid iter_arg");
-  auto it = llvm::find(loopLike.getRegionIterArgs(), iterArg);
+  BlockArgument *it = llvm::find(loopLike.getRegionIterArgs(), iterArg);
   int64_t iterArgIdx = std::distance(loopLike.getRegionIterArgs().begin(), it);
   MatchingSubsets subsets;
   if (failed(subsets.populateSubsetOpsAtIterArg(loopLike, iterArg)))