[mlir][linalg]-Fix wrong assertion in the getMatchingYieldValue interface

In order to have a consistent implementation for getMatchingYieldValue
for linalg generic with buffer/tensor semantics, we should assert the
opOperand index based on the numDpsInits and not numOfResults which may
be zero in the buffer semantics.

Author: amirBish

mlir/include/mlir/Dialect/Linalg/IR/LinalgInterfaces.td

@@ -486,7 +486,7 @@ def LinalgStructuredInterface
         int64_t resultIndex =
             opOperand->getOperandNumber() - $_op.getNumDpsInputs();
         assert(resultIndex >= 0 &&
-               resultIndex < this->getOperation()->getNumResults());
+               resultIndex < $_op.getNumDpsInits());
         Operation *yieldOp = getBlock()->getTerminator();
         return &yieldOp->getOpOperand(resultIndex);
       }]