shview: fix segfault and odd behaviour when lmax exceeds number of coefficients provided
shview: fix segfault and odd behaviour when lmax exceeds number of coefficients provided

MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3