v.buffer: use standardized options (https://trac.osgeo.org/grass/ticket/2409)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@63095 15284696-431f-4ddb-bdfa-cd5b030d7da7

vector/v.buffer/main.c

@@ -268,7 +268,6 @@ int main(int argc, char *argv[])
     angle_opt->guisection = _("Distance");
 
     bufcol_opt = G_define_standard_option(G_OPT_DB_COLUMN);
-    bufcol_opt->key = "bufcolumn";
     bufcol_opt->description =
 	_("Name of column to use for buffer distances");
     bufcol_opt->guisection = _("Distance");