btrfs: remove unused rcu-string printk helpers

The RCU-string API has never taken off and we don't use the printk
helpers provided as we do the protection in our helpers. Remove the "in
RCU" wrappers.

Reviewed-by: Daniel Vacek <neelx@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Author: kdave

fs/btrfs/messages.h

@@ -53,7 +53,7 @@ void _btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...);
 	btrfs_printk(fs_info, KERN_INFO fmt, ##args)
 
 /*
- * Wrappers that use printk_in_rcu
+ * Wrappers that use printk in RCU
  */
 #define btrfs_emerg_in_rcu(fs_info, fmt, args...) \
 	btrfs_printk_in_rcu(fs_info, KERN_EMERG fmt, ##args)
@@ -71,7 +71,7 @@ void _btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...);
 	btrfs_printk_in_rcu(fs_info, KERN_INFO fmt, ##args)
 
 /*
- * Wrappers that use a ratelimited printk_in_rcu
+ * Wrappers that use a ratelimited printk in RCU
  */
 #define btrfs_emerg_rl_in_rcu(fs_info, fmt, args...) \
 	btrfs_printk_rl_in_rcu(fs_info, KERN_EMERG fmt, ##args)

fs/btrfs/rcu-string.h

@@ -32,18 +32,6 @@ static inline struct rcu_string *rcu_string_strdup(const char *src, gfp_t mask)
 	return ret;
 }
 
-#define printk_in_rcu(fmt, ...) do {	\
-	rcu_read_lock();		\
-	printk(fmt, __VA_ARGS__);	\
-	rcu_read_unlock();		\
-} while (0)
-
-#define printk_ratelimited_in_rcu(fmt, ...) do {	\
-	rcu_read_lock();				\
-	printk_ratelimited(fmt, __VA_ARGS__);		\
-	rcu_read_unlock();				\
-} while (0)
-
 #define rcu_str_deref(rcu_str) ({				\
 	struct rcu_string *__str = rcu_dereference(rcu_str);	\
 	__str->str;						\