Remove some stray OPENSSL_EXPORTS in a .cc file

This should be in the header (and is).

Change-Id: If86b6d62ba24d1c80dae171a6ada3a758c81c575
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/92909
Commit-Queue: David Benjamin <davidben@google.com>
Auto-Submit: David Benjamin <davidben@google.com>
Presubmit-BoringSSL-Verified: boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Rudolf Polzer <rpolzer@google.com>

crypto/bio/bio.cc

diff --git a/crypto/bio/bio.cc b/crypto/bio/bio.cc
index d98be33..a2cafeb 100644
--- a/crypto/bio/bio.cc
+++ b/crypto/bio/bio.cc
@@ -334,16 +334,10 @@
   return (int)BIO_ctrl(bio, BIO_CTRL_SET_CLOSE, close_flag, nullptr);
 }
 
-OPENSSL_EXPORT uint64_t BIO_number_read(const BIO *bio) {
-  auto *impl = FromOpaque(bio);
+uint64_t BIO_number_read(const BIO *bio) { return FromOpaque(bio)->num_read; }
 
-  return impl->num_read;
-}
-
-OPENSSL_EXPORT uint64_t BIO_number_written(const BIO *bio) {
-  auto *impl = FromOpaque(bio);
-
-  return impl->num_write;
+uint64_t BIO_number_written(const BIO *bio) {
+  return FromOpaque(bio)->num_write;
 }
 
 BIO *BIO_push(BIO *bio, BIO *appended_bio) {