[mlir][ExecutionEngine] Fix missing return from operator==() in `OwningMemRef` (#179655)
Closes [#91233](https://github.com/llvm/llvm-project/issues/91233)
mlir/include/mlir/ExecutionEngine/MemRefUtils.h:190:No 'return'
statement in non-void function
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Co-authored-by: braam-76 <braam67.gamidov@yandex.com>