strassen is incorrectly initialized

[henrikvalter]

Strassen should compute a matrix multiplication C = A * B. Right now, matrices A and B are initialized, but then both strassen_main_par and strassen_main_seq are called to compute A = B * C instead. And since C is uninitialized, the result will mostly be 0.

If using validation, compare_matrix will calculate the relative difference between two cells of the parallel and sequential result. For most cells this will be (0-0)/0, which is of course undefined and passes the validation for whatever reason.

A simple fix could be to call the main functions as strassen_main_par(A,B,C,bots_arg_size) instead of strassen_main_par(C, A, B, bots_arg_size) in app-desc.h.