perli11ndoc: fix the synopsis formatting for class struct functions
perli11ndoc: fix the synopsis formatting for class struct functions

cpanxaoc/perl-Glib-Object-Introspection,cpanxaoc/perl-Glib-Object-Introspection,GNOME/perl-Glib-Object-Introspection,GNOME/perl-Glib-Object-Introspection