Return dummy true on compat module function

Make compatibility module function to always return a value to be able
to check function result either new main version or compat version is
called.

Adapt cmake, perl, python and ruby compat module function to return a
true value. Always true is returned as compat version does not handle
returning error exit code.

init/cmake.in

@@ -43,5 +43,7 @@ endif()
 @compatversion@         include(${tempfile_name})
 @compatversion@         file(REMOVE ${tempfile_name})
 @compatversion@      endif()
+@compatversion@      # return value as done on new main version
+@compatversion@      set(module_result TRUE PARENT_SCOPE)
 @compatversion@   endfunction(module)
 @compatversion@endif()

init/perl.pm.in

@@ -30,10 +30,7 @@ undef $_mlre;
 @compatversion@   { no warnings 'redefine';
 @compatversion@      *module = sub {
 @compatversion@         eval `@libexecdir@/modulecmd-compat perl @_`;
-@compatversion@         if ($@) {
-@compatversion@            use Carp;
-@compatversion@            confess "module-error: $@\n";
-@compatversion@         }
+@compatversion@         # return value as done on new main version
 @compatversion@         return 1;
 @compatversion@      };
 @compatversion@   }

init/python.py.in

@@ -30,3 +30,5 @@ del _mlre
 @compatversion@   # set module command in accordance with active version
 @compatversion@   def module(command, *arguments):
 @compatversion@      exec(subprocess.Popen(['@libexecdir@/modulecmd-compat', 'python', command] + list(arguments), stdout=subprocess.PIPE).communicate()[0])
+@compatversion@      # return value as done on new main version
+@compatversion@      return True

init/ruby.rb.in

@@ -34,6 +34,8 @@ eval `#{_mlre}@TCLSH@ @libexecdir@/modulecmd.tcl ruby autoinit`
 @compatversion@            args = args.join(' ')
 @compatversion@         end
 @compatversion@         eval `@libexecdir@/modulecmd-compat ruby #{args}`
+@compatversion@         # return value as done on new main version
+@compatversion@         return true
 @compatversion@      end
 @compatversion@   end
 @compatversion@end