vboot: Do not use hashed-strings offset

The hashed-strings signature property includes two uint32_t values.
The first is unneeded as there should never be a start offset into the
strings region. The second, the size, is needed because the added
signature node appends to this region.

See tools/image-host.c, where a static 0 value is used for the offset.

Signed-off-by: Teddy Reed <teddy.reed@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/common/image-sig.c b/common/image-sig.c
index 8d2fd10..5a269d3 100644
--- a/common/image-sig.c
+++ b/common/image-sig.c
@@ -377,8 +377,11 @@
 	/* Add the strings */
 	strings = fdt_getprop(fit, noffset, "hashed-strings", NULL);
 	if (strings) {
-		fdt_regions[count].offset = fdt_off_dt_strings(fit) +
-				fdt32_to_cpu(strings[0]);
+		/*
+		 * The strings region offset must be a static 0x0.
+		 * This is set in tool/image-host.c
+		 */
+		fdt_regions[count].offset = fdt_off_dt_strings(fit);
 		fdt_regions[count].size = fdt32_to_cpu(strings[1]);
 		count++;
 	}