remove checks for error states that will not occur
remove checks for error states that will not occur

MichaelClerx/libcellml,nickerso/libcellml,cellml/libcellml,cellml/libcellml,cellml/libcellml,hsorby/libcellml,MichaelClerx/libcellml,hsorby/libcellml,hsorby/libcellml,libcellml/buildbot-testing,nickerso/libcellml,nickerso/libcellml,libcellml/buildbot-testing,hsorby/libcellml,nickerso/libcellml,MichaelClerx/libcellml,cellml/libcellml