vfs: fix check for fallocate on active swapfile

Fix the broken check for calling sys_fallocate() on an active swapfile,
introduced by commit 0790b31b69374ddadefe ("fs: disallow all fallocate
operation on active swapfile").

Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/open.c b/fs/open.c
index 36662d0..d6fd3ac 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -263,11 +263,10 @@
 		return -EPERM;
 
 	/*
-	 * We can not allow to do any fallocate operation on an active
-	 * swapfile
+	 * We cannot allow any fallocate operation on an active swapfile
 	 */
 	if (IS_SWAPFILE(inode))
-		ret = -ETXTBSY;
+		return -ETXTBSY;
 
 	/*
 	 * Revalidate the write permissions, in case security policy has