[mlir][linalg] fix switch case for conv-vec to have brackets

[raikonenfnu]

Summary

Windows build requires brackets on switch-cases that initializes
variables.

[raikonenfnu]

This should fix the initialization of '<some variable>' is skipped by 'default' label

mlir/lib/Dialect/Linalg/Transforms/Vectorization.cpp

FailureOr<Operation *> conv(Conv1DOpOrder conv1DOpOrder) {
 
     // The base vectorization case is input: {n,w,c}, weight: {kw,c,f}, output:
     // {n,w,f}. To reuse the base pattern vectorization case, we do pre
     // transpose on input, weight, and output.
     switch (conv1DOpOrder) {
     case Conv1DOpOrder::Nwc:
       // Base case, so no transposes necessary.
       break;
-    case Conv1DOpOrder::Ncw:
+    case Conv1DOpOrder::Ncw: {
       // To match base vectorization case, we pre-transpose current case.
       // ncw -> nwc
       static constexpr std::array<int64_t, 3> permLhs = {0, 2, 1};
       lhs = builder.create<vector::TransposeOp>(loc, lhs, permLhs);
       // fcw -> wcf
       static constexpr std::array<int64_t, 3> permRhs = {2, 1, 0};
       rhs = builder.create<vector::TransposeOp>(loc, rhs, permRhs);
       // nfw -> nwf
       static constexpr std::array<int64_t, 3> permRes = {0, 2, 1};
       res = builder.create<vector::TransposeOp>(loc, res, permRes);
       break;
+    }
     default:
       return failure();
     }
 
     //===------------------------------------------------------------------===//
     // Begin vector-only rewrite part
     //===------------------------------------------------------------------===//
     // Unroll along kw and read slices of lhs and rhs.
FailureOr<Operation *> conv(Conv1DOpOrder conv1DOpOrder) {
 
     // The base vectorization case is output: {n,w,f}
     // To reuse the result from base pattern vectorization case, we post
     // transpose the base case result.
     switch (conv1DOpOrder) {
     case Conv1DOpOrder::Nwc:
       // Base case, so no transposes necessary.
       break;
-    case Conv1DOpOrder::Ncw:
+    case Conv1DOpOrder::Ncw: {
       // nwf -> nfw
       static constexpr std::array<int64_t, 3> perm = {0, 2, 1};
       res = builder.create<vector::TransposeOp>(loc, res, perm);
       break;
+    }
     default:
       return failure();
     }
 
     // Write back res slice of size {n, w, f} @ [0, 0, 0].
     return builder
         .create<vector::TransferWriteOp>(loc, res, resShaped,
                                          ValueRange{zero, zero, zero})