param: make param sections const.

Since this section can be read-only (they're in .rodata), they should
always have been const.  Minor flow-through various functions.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>

include/linux/moduleparam.h

@@ -161,7 +161,7 @@ __check_old_set_param(int (*oldset)(const char *, struct kernel_param *))
 /* Called on module insert or kernel boot */
 extern int parse_args(const char *name,
 		      char *args,
-		      struct kernel_param *params,
+		      const struct kernel_param *params,
 		      unsigned num,
 		      int (*unknown)(char *param, char *val));