[mlir][sparse] fix typos in integration tests

mlir/test/Integration/Dialect/SparseTensor/CPU/sparse_out_reduction.mlir

func @entry() {
     %t2 = arith.constant sparse<
        [ [1,0,0], [1,1,3], [2,2,1], [2,2,3] ], [ 6, 7, 8, 9 ]
     > : tensor<3x3x4xi32>
     %st1 = sparse_tensor.convert %t1
       : tensor<3x3x4xi32> to tensor<?x?x?xi32, #SparseTensor>
     %st2 = sparse_tensor.convert %t2
       : tensor<3x3x4xi32> to tensor<?x?x?xi32, #SparseTensor>
 
-
     // Call kernel.
     %0 = call @redsum(%st1, %st2)
       : (tensor<?x?x?xi32, #SparseTensor>,
          tensor<?x?x?xi32, #SparseTensor>) -> tensor<?x?xi32, #SparseMatrix>
 
     //
     // Verify results. Only two entries stored in result. Correct structure.
     //

mlir/test/Integration/Dialect/SparseTensor/CPU/sparse_out_simple.mlir

#DCSR = #sparse_tensor.encoding<{
   dimOrdering = affine_map<(i,j) -> (i,j)>
 }>
 
 #eltwise_mult = {
   indexing_maps = [
     affine_map<(i,j) -> (i,j)>  // X (out)
   ],
   iterator_types = ["parallel", "parallel"],
-  doc = "X(i,j) += X(i,j) * X(i,j)"
+  doc = "X(i,j) *= X(i,j)"
 }
 
 //
 // Integration test that lowers a kernel annotated as sparse to
 // actual sparse code, initializes a matching sparse storage scheme
 // from file, and runs the resulting code with the JIT compiler.
 //
 module {