init: Suppress wrong warning for bootconfig cmdline parameter

Since the 'bootconfig' command line parameter is handled before
parsing the command line, it doesn't use early_param(). But in
this case, kernel shows a wrong warning message about it.

[    0.013714] Kernel command line: ro console=ttyS0  bootconfig console=tty0
[    0.013741] Unknown command line parameters: bootconfig

To suppress this message, add a dummy handler for 'bootconfig'.

Link: https://lkml.kernel.org/r/162812945097.77369.1849780946468010448.stgit@devnote2

Fixes: 86d1919a4f ("init: print out unknown kernel parameters")
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

init/main.c

@@ -397,6 +397,12 @@ static int __init bootconfig_params(char *param, char *val,
 	return 0;
 }
 
+static int __init warn_bootconfig(char *str)
+{
+	/* The 'bootconfig' has been handled by bootconfig_params(). */
+	return 0;
+}
+
 static void __init setup_boot_config(void)
 {
 	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
@@ -475,9 +481,8 @@ static int __init warn_bootconfig(char *str)
 	pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
 	return 0;
 }
-early_param("bootconfig", warn_bootconfig);
-
 #endif
+early_param("bootconfig", warn_bootconfig);
 
 /* Change NUL term back to "=", to make "param" the whole string. */
 static void __init repair_env_string(char *param, char *val)