maint: Replace argc variable name with nargin in C++ code. * cellfun.cc (Fnum2cell): Remove extra space in nargin declaration. * error.cc (Fwarning): Rename argc variable to nargin and update code. * graphics.cc (create): Surround tertiary expression with parentheses before assignment to variable. * pager.cc (Fmore): Rename argc variable to nargin and update code. Replace make_argv() with xstring_value() call. Make error messages more specific. * pr-output.cc (Fformat): Return empty octave_value_list rather than declaring retval and then returning it. * variables.cc (Fwho, Fwhos): Remove unused variable retval. * variables.cc (Fclear): Return empty octave_value_list rather than declaring retval and then returning it. * pt-funcall.cc (print_raw): Rename variable "len" to "n" for clarity.

--- a/libinterp/corefcn/pr-output.cc	Mon Dec 14 14:34:57 2015 -0800
+++ b/libinterp/corefcn/pr-output.cc	Mon Dec 14 15:34:39 2015 -0800
@@ -4033,15 +4033,13 @@
 @seealso{fixed_point_format, output_max_field_width, output_precision, split_long_rows, print_empty_dimensions, rats}\n\
 @end deftypefn")
 {
-  octave_value_list retval;
-
   int argc = args.length () + 1;
 
   string_vector argv = args.make_argv ("format");
 
   set_format_style (argc, argv);
 
-  return retval;
+  return octave_value_list ();
 }
 
 DEFUN (__compactformat__, args, nargout,