Remove duplicated copy/paste residue

Signed-off-by: Fabio Utzig <utzig@apache.org>
diff --git a/boot/bootutil/src/image_validate.c b/boot/bootutil/src/image_validate.c
index 5b2b9a0..a854fd3 100644
--- a/boot/bootutil/src/image_validate.c
+++ b/boot/bootutil/src/image_validate.c
@@ -60,12 +60,10 @@
 
     /* in some cases (split image) the hash is seeded with data from
      * the loader image */
-    if(seed && (seed_len > 0)) {
+    if (seed && (seed_len > 0)) {
         bootutil_sha256_update(&sha256_ctx, seed, seed_len);
     }
 
-    size = hdr->ih_img_size + hdr->ih_hdr_size;
-
     /*
      * Hash is computed over image header and image itself. No TLV is
      * included ATM.