Use C99 for size_t loops.

This was done just by grepping for 'size_t i;' and 'size_t j;'. I left
everything in crypto/x509 and friends alone.

There's some instances in gcm.c that are non-trivial and pulled into a
separate CL for ease of review.

Change-Id: I6515804e3097f7e90855f1e7610868ee87117223
Reviewed-on: https://boringssl-review.googlesource.com/10801
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
diff --git a/ssl/ssl_asn1.c b/ssl/ssl_asn1.c
index 4409f35..6395a00 100644
--- a/ssl/ssl_asn1.c
+++ b/ssl/ssl_asn1.c
@@ -340,8 +340,7 @@
       OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
       goto err;
     }
-    size_t i;
-    for (i = 0; i < sk_X509_num(in->cert_chain); i++) {
+    for (size_t i = 0; i < sk_X509_num(in->cert_chain); i++) {
       if (!ssl_add_cert_to_cbb(&child, sk_X509_value(in->cert_chain, i))) {
         goto err;
       }