[MLIR][NFC] Fix a checked after used case in ReshapeOpsUtils.cpp

[xgupta]

Summary

Found by PVS-Studio - https://pvs-studio.com/en/blog/posts/cpp/1003/, N18.
The value of the 'sourceDim' index is checked after it was used.

[zero9178]

LGTM Thanks!

mlir/lib/Dialect/Utils/ReshapeOpsUtils.cpp

mlir::getReassociationIndicesForCollapse(ArrayRef<int64_t> sourceShape,
   while (sourceDim < sourceShape.size()) {
     unsigned targetDim = reassociationMap.size();
     // If we have mapped all the target dimensions stop and handle the remaining
     // tail of size-1 dimensions explictly.
     if (targetDim == targetShape.size())
       break;
 
     int64_t currTargetShape = targetShape[targetDim];
-    while (sourceShape[sourceDim] != ShapedType::kDynamic &&
-           prodOfCollapsedDims * sourceShape[sourceDim] < currTargetShape &&
-           sourceDim < sourceShape.size()) {
+    while (sourceDim < sourceShape.size() &&
+           sourceShape[sourceDim] != ShapedType::kDynamic &&
+           prodOfCollapsedDims * sourceShape[sourceDim] < currTargetShape) {
       prodOfCollapsedDims *= sourceShape[sourceDim];
       currIndices.push_back(sourceDim++);
     }
 
     // If the current expanded dimension is dynamic, then the collapsed
     // dimensions should also be dynamic and product of all previous unprocessed
     // dimensions of the expanded shape should be 1.
     if (sourceShape[sourceDim] == ShapedType::kDynamic &&