ANDROID: Incremental fs: Add FS_IOC_MEASURE_VERITY

Add ioctl to return the verity file digest, compatible with the identical
ioctl in fs/verity/.

Bug: 160634504
Test: incfs_test passes
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Change-Id: I1bc2dc975b9be122e1c831a25a1d44f27a360f3c
diff --git a/fs/incfs/verity.h b/fs/incfs/verity.h
index b569ff42..3ba2306 100644
--- a/fs/incfs/verity.h
+++ b/fs/incfs/verity.h
@@ -12,6 +12,7 @@
 #ifdef CONFIG_FS_VERITY
 
 int incfs_ioctl_enable_verity(struct file *filp, const void __user *uarg);
+int incfs_ioctl_measure_verity(struct file *filp, void __user *_uarg);
 
 int incfs_fsverity_file_open(struct inode *inode, struct file *filp);
 
@@ -23,6 +24,12 @@ static inline int incfs_ioctl_enable_verity(struct file *filp,
 	return -EOPNOTSUPP;
 }
 
+static inline int incfs_ioctl_measure_verity(struct file *filp,
+					     void __user *_uarg)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline int incfs_fsverity_file_open(struct inode *inode,
 					   struct file *filp)
 {