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>
diff --git a/kernel/params.c b/kernel/params.c
index b6554aa..93a380a 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -325,10 +325,11 @@
 }
 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,