module: export param_free_charp()

Change the param_free_charp() function from static to exported.

It is used by zswap in the next patch ("zswap: use charp for zswap param
strings").
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Seth Jennings <sjennings@variantweb.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/moduleparam.h

@@ -386,6 +386,7 @@ extern int param_get_ullong(char *buffer, const struct kernel_param *kp);
 extern const struct kernel_param_ops param_ops_charp;
 extern int param_set_charp(const char *val, const struct kernel_param *kp);
 extern int param_get_charp(char *buffer, const struct kernel_param *kp);
+extern void param_free_charp(void *arg);
 #define param_check_charp(name, p) __param_check(name, p, char *)
 
 /* We used to allow int as well as bool.  We're taking that away! */

kernel/params.c

@@ -325,10 +325,11 @@ int param_get_charp(char *buffer, const struct kernel_param *kp)
 }
 EXPORT_SYMBOL(param_get_charp);
 
-static void param_free_charp(void *arg)
+void param_free_charp(void *arg)
 {
 	maybe_kfree_parameter(*((char **)arg));
 }
+EXPORT_SYMBOL(param_free_charp);
 
 const struct kernel_param_ops param_ops_charp = {
 	.set = param_set_charp,