fs: fix incorrect fmode_t casts

Use __FMODE_NONOTIFY instead of FMODE_NONOTIFY to fixes
the following sparce warnings:
fs/overlayfs/file.c:48:37: sparse: warning: restricted fmode_t degrades to integer
fs/overlayfs/file.c:128:13: sparse: warning: restricted fmode_t degrades to integer
fs/open.c:1159:21: sparse: warning: restricted fmode_t degrades to integer
Signed-off-by: Min-Hua Chen <minhuadotchen@gmail.com>
Message-Id: <20230502232210.119063-1-minhuadotchen@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs/open.c

@@ -1148,7 +1148,7 @@ inline struct open_how build_open_how(int flags, umode_t mode)
 inline int build_open_flags(const struct open_how *how, struct open_flags *op)
 {
 	u64 flags = how->flags;
-	u64 strip = FMODE_NONOTIFY | O_CLOEXEC;
+	u64 strip = __FMODE_NONOTIFY | O_CLOEXEC;
 	int lookup_flags = 0;
 	int acc_mode = ACC_MODE(flags);
 

fs/overlayfs/file.c

@@ -35,7 +35,7 @@ static char ovl_whatisit(struct inode *inode, struct inode *realinode)
 }
 
 /* No atime modification nor notify on underlying */
-#define OVL_OPEN_FLAGS (O_NOATIME | FMODE_NONOTIFY)
+#define OVL_OPEN_FLAGS (O_NOATIME | __FMODE_NONOTIFY)
 
 static struct file *ovl_open_realfile(const struct file *file,
 				      const struct path *realpath)