um: console: Ignore console= option

Ignore linux kernel's console= option at uml's console
option handler. Since uml's con= option is only for
setting up new console, and Linux kernel's console=
option specify to which console kernel output its
message, we can use both option for different purpose.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NRichard Weinberger <richard@nod.at>

arch/um/drivers/stdio_console.c

@@ -192,6 +192,9 @@ __uml_exitcall(console_exit);
 
 static int console_chan_setup(char *str)
 {
+	if (!strncmp(str, "sole=", 5))	/* console= option specifies tty */
+		return 0;
+
 	line_setup(vt_conf, MAX_TTYS, &def_conf, str, "console");
 	return 1;
 }