f2fs: make clear on test condition and return types

This patch adds a parentheses to make clear for condition check.
And also it changes the return type for better meanings.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c8288c9..2e4aa3a 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1442,5 +1442,5 @@
 int f2fs_convert_inline_data(struct inode *, pgoff_t, struct page *);
 int f2fs_write_inline_data(struct inode *, struct page *, unsigned int);
 void truncate_inline_data(struct inode *, u64);
-int recover_inline_data(struct inode *, struct page *);
+bool recover_inline_data(struct inode *, struct page *);
 #endif