maint: Clean up code based on static analysis suggestions. * __dispatch__.cc (F__dispatch__): Eliminate unnecessary double check on (nargin > 0). * cellfun.cc (Fnum2cell): Eliminate duplicate else-if branch for array.is_object(). * load-save.cc: Eliminate unreachable else branch. Simplify else-if to simple else since condition is always true at this point. * matrix_type.cc (Fmatrix_type): Eliminate unnecessary check on 'str_type == upper' and just mark matrix as permuted when permutation matrix was given as input. * kpse.cc (set_end): remove unused variable and its usage in conditional.