[truetype] Avoid sanitizer warning (#57289).

* src/truetype/ttpload.c (tt_face_get_device_metrics): Use
`FT_OFFSET'.
diff --git a/ChangeLog b/ChangeLog
index 4b0ba72..d5ef22e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2019-11-23  Werner Lemberg  <wl@gnu.org>
+
+	[truetype] Avoid sanitizer warning (#57289).
+
+	* src/truetype/ttpload.c (tt_face_get_device_metrics): Use
+	`FT_OFFSET'.
+
 2019-11-23  Armin Hasitzka  <prince.cherusker@gmail.com>
 
 	[truetype] Fix integer overflow (#57287).
diff --git a/src/truetype/ttpload.c b/src/truetype/ttpload.c
index bc954c2..cedbe25 100644
--- a/src/truetype/ttpload.c
+++ b/src/truetype/ttpload.c
@@ -633,7 +633,7 @@
     FT_UInt   nn;
     FT_Byte*  result      = NULL;
     FT_ULong  record_size = face->hdmx_record_size;
-    FT_Byte*  record      = face->hdmx_table + 8;
+    FT_Byte*  record      = FT_OFFSET( face->hdmx_table, 8 );
 
 
     for ( nn = 0; nn < face->hdmx_record_count; nn++ )