vbe: Drop the U-Boot prefix from the version

We don't need the U-Boot prefix on the version and in fact it is harmful
since pytest gets confused seeing the U-Boot banner bring displayed when
the version is printed.

Drop the prefix from the string.

We could produce an entirely new string from the component parts, but this
adds to the rodata size and would break the use of version_string as the
only thing which holds this information.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/vbe_simple_os.c b/boot/vbe_simple_os.c
index 7761b9e..058db61 100644
--- a/boot/vbe_simple_os.c
+++ b/boot/vbe_simple_os.c
@@ -18,7 +18,7 @@
 
 int vbe_simple_fixup_node(ofnode node, struct simple_state *state)
 {
-	char *version;
+	const char *version, *str;
 	int ret;
 
 	version = strdup(state->fw_version);
@@ -31,7 +31,12 @@
 	ret = ofnode_write_u32(node, "cur-vernum", state->fw_vernum);
 	if (ret)
 		return log_msg_ret("num", ret);
-	ret = ofnode_write_string(node, "bootloader-version", version_string);
+
+	/* Drop the 'U-Boot ' at the start */
+	str = version_string;
+	if (!strncmp("U-Boot ", str, 7))
+		str += 7;
+	ret = ofnode_write_string(node, "bootloader-version", str);
 	if (ret)
 		return log_msg_ret("bl", ret);