libfdt: Drop -FDT_ERR_TOODEEP

This error code has not been upstreamed and is not really needed since it
is unlikely to be triggered. Drop it to maintain compatability with
upstream.

Reported-by: Peter Robinson <pbrobinson@gmail.com>

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
diff --git a/lib/libfdt/fdt_region.c b/lib/libfdt/fdt_region.c
index 8b8a547..63099f1 100644
--- a/lib/libfdt/fdt_region.c
+++ b/lib/libfdt/fdt_region.c
@@ -397,7 +397,7 @@
 			last_node = offset;
 			p.depth++;
 			if (p.depth == FDT_MAX_DEPTH)
-				return -FDT_ERR_TOODEEP;
+				return -FDT_ERR_BADSTRUCTURE;
 			name = fdt_get_name(fdt, offset, &len);
 			if (p.end - path + 2 + len >= path_len)
 				return -FDT_ERR_NOSPACE;