base: Simplify the construction of MD5Digest.

base/md5.cc

Index: base/md5.cc
diff --git a/base/md5.cc b/base/md5.cc
index 9709a86fcd166194d0a9547f6899b55140b70ebc..9cbb44bad7685e4a87bbc6614677fa2e9a092a79 100644
--- a/base/md5.cc
+++ b/base/md5.cc
@@ -256,7 +256,7 @@ void MD5Final(MD5Digest* digest, MD5Context* context) {
 
   MD5Transform(ctx->buf, (uint32_t*)ctx->in);
   byteReverse((uint8_t*)ctx->buf, 4);
-  memcpy(digest->a, ctx->buf, 16);
+  memcpy(digest, ctx->buf, 16);
   memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
 }
 
@@ -275,9 +275,8 @@ std::string MD5DigestToBase16(const MD5Digest& digest) {
   ret.resize(32);
 
   for (int i = 0, j = 0; i < 16; i++, j += 2) {
-    uint8_t a = digest.a[i];
-    ret[j] = zEncode[(a >> 4) & 0xf];
-    ret[j + 1] = zEncode[a & 0xf];
+    ret[j] = zEncode[(digest[i] >> 4) & 0xf];
+    ret[j + 1] = zEncode[digest[i] & 0xf];
   }
   return ret;
 }