Never define the generated rpc server main function with storage type

"static". The header file generated by "rpcgen -h" will always declare
it as extern, leading to a "static after extern" error being issued by
gcc-4.2. This caused only a warning in gcc-3.x, but it has been wrong
all the time.

This change does not modify the code generated by "rpcgen -m", it only
affects rpcgen used to generate server stubs with a local main function.

This is the minimal patch. It does not remove the now obsolete "storage"
parameter from write_program() and write_programs() in an attempt to keep
differences to other systems' versions of rpcgen as small as possible.

usr.bin/rpcgen/rpc_svcout.c

@@ -126,7 +126,7 @@ serviced */\n");
 		write_svc_aux(nomain);
 	}
 	/* write out dispatcher and stubs */
-	write_programs(nomain? (char *)NULL : "static");
+	write_programs((char *)NULL);
 
 	if (nomain)
 		return;