kernel/params.c: export param_ops_bool_enable_only

This will grant access to this helper to code built as modules.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Kyle McMartin <kyle@kernel.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/kernel/params.c b/kernel/params.c
index 324624e..7edf31f 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -364,6 +364,7 @@
 	.set = param_set_bool_enable_only,
 	.get = param_get_bool,
 };
+EXPORT_SYMBOL_GPL(param_ops_bool_enable_only);
 
 /* This one must be bool. */
 int param_set_invbool(const char *val, const struct kernel_param *kp)