fs/bad_inode.c: is_bad_inode can be boolean

This patch makes is_bad_inode return bool to improve
readability due to this particular function only using either
one or zero as its return value.

No functional change.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4b23def..6b33ac4 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2371,7 +2371,7 @@
 
 /* Invalid inode operations -- fs/bad_inode.c */
 extern void make_bad_inode(struct inode *);
-extern int is_bad_inode(struct inode *);
+extern bool is_bad_inode(struct inode *);
 
 #ifdef CONFIG_BLOCK
 /*