[mlir][tosa] Fix out-of-boundaries iteration for tosa-to-linalg

[mlir][tosa] Fix out-of-boundaries iteration for tosa-to-linalg

When the number of elements of two shapes are not equal, a Reshape operation cannot be used to transfer one into another

Function findIntermediateShape(...) can cause out-of-boundaries operator[] call if the abovementioned condition strikes

The test-case I used now causes no error as its root-cause was an issue in Tosa dialect with padded Conv2D operations lowering which is already solved in commit 69c984b6

Reviewed By: rsuderman

Differential Revision: https://reviews.llvm.org/D140013