init/main.c: silence some -Wunused-parameter warnings

There are a bunch of callbacks with unused arguments, go ahead and silence
those so "make KCFLAGS=-W init/main.o" is a little quieter.  Here's a
little sample:

init/main.c:182:43: warning: unused parameter 'str' [-Wunused-parameter]
static int __init set_reset_devices(char *str)

Link: https://lkml.kernel.org/r/20210519162341.1275452-1-ahalaney@redhat.com
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

init/main.c

@@ -181,7 +181,7 @@ EXPORT_SYMBOL_GPL(static_key_initialized);
 unsigned int reset_devices;
 EXPORT_SYMBOL(reset_devices);
 
-static int __init set_reset_devices(char *str)
+static int __init set_reset_devices(char *str __always_unused)
 {
 	reset_devices = 1;
 	return 1;
@@ -231,13 +231,13 @@ static bool __init obsolete_checksetup(char *line)
 unsigned long loops_per_jiffy = (1<<12);
 EXPORT_SYMBOL(loops_per_jiffy);
 
-static int __init debug_kernel(char *str)
+static int __init debug_kernel(char *str __always_unused)
 {
 	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
 	return 0;
 }
 
-static int __init quiet_kernel(char *str)
+static int __init quiet_kernel(char *str __always_unused)
 {
 	console_loglevel = CONSOLE_LOGLEVEL_QUIET;
 	return 0;
@@ -474,7 +474,7 @@ static void __init setup_boot_config(void)
 	get_boot_config_from_initrd(NULL);
 }
 
-static int __init warn_bootconfig(char *str)
+static int __init warn_bootconfig(char *str __always_unused)
 {
 	pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
 	return 0;
@@ -503,7 +503,8 @@ static void __init repair_env_string(char *param, char *val)
 
 /* Anything after -- gets handed straight to init. */
 static int __init set_init_arg(char *param, char *val,
-			       const char *unused, void *arg)
+			       const char *unused __always_unused,
+			       void *arg __always_unused)
 {
 	unsigned int i;
 
@@ -528,7 +529,8 @@ static int __init set_init_arg(char *param, char *val,
  * unused parameters (modprobe will find them in /proc/cmdline).
  */
 static int __init unknown_bootoption(char *param, char *val,
-				     const char *unused, void *arg)
+				     const char *unused __always_unused,
+				     void *arg __always_unused)
 {
 	size_t len = strlen(param);
 
@@ -728,7 +730,8 @@ noinline void __ref rest_init(void)
 
 /* Check for early params. */
 static int __init do_early_param(char *param, char *val,
-				 const char *unused, void *arg)
+				 const char *unused __always_unused,
+				 void *arg __always_unused)
 {
 	const struct obs_kernel_param *p;
 
@@ -1347,8 +1350,10 @@ static const char *initcall_level_names[] __initdata = {
 	"late",
 };
 
-static int __init ignore_unknown_bootoption(char *param, char *val,
-			       const char *unused, void *arg)
+static int __init ignore_unknown_bootoption(char *param __always_unused,
+					    char *val __always_unused,
+					    const char *unused __always_unused,
+					    void *arg __always_unused)
 {
 	return 0;
 }
@@ -1487,7 +1492,7 @@ void __weak free_initmem(void)
 	free_initmem_default(POISON_FREE_INITMEM);
 }
 
-static int __ref kernel_init(void *unused)
+static int __ref kernel_init(void *unused __always_unused)
 {
 	int ret;