Minor include cleanup.

Found by Clang-Tidy during release.

Change-Id: I70e7d3087bedaaee5a3ce50bc63d630b6a6a6964
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/100427
Commit-Queue: Xiangfei Ding <xfding@google.com>
Auto-Submit: Rudolf Polzer <rpolzer@google.com>
Reviewed-by: Xiangfei Ding <xfding@google.com>
Commit-Queue: Rudolf Polzer <rpolzer@google.com>

bench/ecdh.cc

diff --git a/bench/ecdh.cc b/bench/ecdh.cc
index 56502ca..f7e8b9c 100644
--- a/bench/ecdh.cc
+++ b/bench/ecdh.cc
@@ -16,6 +16,7 @@
 
 #include <openssl/base.h>
 #include <openssl/ec.h>
+#include <openssl/ec_key.h>
 #include <openssl/ecdh.h>
 #include <openssl/err.h>
 #include <openssl/evp.h>

bench/ecdsa.cc

diff --git a/bench/ecdsa.cc b/bench/ecdsa.cc
index 8a81ddf..ce6bc5e 100644
--- a/bench/ecdsa.cc
+++ b/bench/ecdsa.cc
@@ -13,7 +13,6 @@
 // limitations under the License.
 
 #include <cstring>
-#include <vector>
 
 #include <benchmark/benchmark.h>