fs/sysv: dereferencing ERR_PTR()

I moved the dir_put_page() inside the if condition so we don't dereference
"page", if it's an ERR_PTR().

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/sysv/dir.c b/fs/sysv/dir.c
index 4e50286..1dabed2 100644
--- a/fs/sysv/dir.c
+++ b/fs/sysv/dir.c
@@ -164,8 +164,8 @@
 							name, de->name))
 					goto found;
 			}
+			dir_put_page(page);
 		}
-		dir_put_page(page);
 
 		if (++n >= npages)
 			n = 0;