fscrypt: make ->dummy_context() return bool

This makes it consistent with ->is_encrypted(), ->empty_dir(), and
fscrypt_dummy_context_enabled().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 6492047..116fc2a 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1166,7 +1166,7 @@
 	return res;
 }
 
-static int ext4_dummy_context(struct inode *inode)
+static bool ext4_dummy_context(struct inode *inode)
 {
 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
 }