Fix Coverity 1503314 unchecked return value

Reviewed-by: David von Oheimb <david.von.oheimb@siemens.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18013)
diff --git a/apps/speed.c b/apps/speed.c
index b6e7d36..3776866 100644
--- a/apps/speed.c
+++ b/apps/speed.c
@@ -736,7 +736,7 @@
             rc = EVP_DecryptUpdate(ctx, buf, &outl, buf, lengths[testnum]);
             if (rc != 1) {
                 /* reset iv in case of counter overflow */
-                EVP_CipherInit_ex(ctx, NULL, NULL, NULL, iv, -1);
+                (void)EVP_CipherInit_ex(ctx, NULL, NULL, NULL, iv, -1);
             }
         }
     } else {
@@ -744,7 +744,7 @@
             rc = EVP_EncryptUpdate(ctx, buf, &outl, buf, lengths[testnum]);
             if (rc != 1) {
                 /* reset iv in case of counter overflow */
-                EVP_CipherInit_ex(ctx, NULL, NULL, NULL, iv, -1);
+                (void)EVP_CipherInit_ex(ctx, NULL, NULL, NULL, iv, -1);
             }
         }
     }