fsnotify: return non const from fsnotify_data_inode()

Return non const inode pointer from fsnotify_data_inode().
None of the fsnotify hooks pass const inode pointer as data and
callers often need to cast to a non const pointer.

Link: https://lore.kernel.org/r/20200708111156.24659-3-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/notify/fanotify/fanotify.c

@@ -341,7 +341,7 @@ static struct inode *fanotify_fid_inode(struct inode *to_tell, u32 event_mask,
 	if (event_mask & ALL_FSNOTIFY_DIRENT_EVENTS)
 		return to_tell;
 
-	return (struct inode *)fsnotify_data_inode(data, data_type);
+	return fsnotify_data_inode(data, data_type);
 }
 
 struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,

include/linux/fsnotify_backend.h

@@ -220,12 +220,11 @@ enum fsnotify_data_type {
 	FSNOTIFY_EVENT_INODE,
 };
 
-static inline const struct inode *fsnotify_data_inode(const void *data,
-						      int data_type)
+static inline struct inode *fsnotify_data_inode(const void *data, int data_type)
 {
 	switch (data_type) {
 	case FSNOTIFY_EVENT_INODE:
-		return data;
+		return (struct inode *)data;
 	case FSNOTIFY_EVENT_PATH:
 		return d_inode(((const struct path *)data)->dentry);
 	default: