Removed k<=m check on JNI binding of the Vandermonde matrix creation function

Removed k<=m check on JNI binding of the reed_sol_vandermonde_coding_matrix function.
It looks like that check is not necessary as both [Jerasure docs](http://web.eecs.utk.edu/~plank/plank/papers/CS-08-627.pdf) and examples support cases where k>m.