fs: edit a comment made in bad taste

I know nobody likes a buzzkill, but I figure it's best to keep the
bad jokes appropriate for small children.

Signed-off-by: Paul Moore <paul@paul-moore.com>

include/linux/fs_context.h

@@ -99,7 +99,7 @@ struct fs_context {
 	const struct cred	*cred;		/* The mounter's credentials */
 	struct p_log		log;		/* Logging buffer */
 	const char		*source;	/* The source name (eg. dev path) */
-	void			*security;	/* Linux S&M options */
+	void			*security;	/* LSM options */
 	void			*s_fs_info;	/* Proposed s_fs_info */
 	unsigned int		sb_flags;	/* Proposed superblock flags (SB_*) */
 	unsigned int		sb_flags_mask;	/* Superblock flags that were changed */