fix ls.schur_mumps: convert matrix to COO format
fix ls.schur_mumps: convert matrix to COO format

BubuLK/sfepy,vlukes/sfepy,BubuLK/sfepy,rc/sfepy,BubuLK/sfepy,vlukes/sfepy,sfepy/sfepy,rc/sfepy,rc/sfepy,sfepy/sfepy,vlukes/sfepy,sfepy/sfepy