benchmark: Add comma at end of help message
The help message was missing a comma after "hmac_drbg". Add the missing
comma.
diff --git a/programs/test/benchmark.c b/programs/test/benchmark.c
index ef83dc1..89fdb84 100644
--- a/programs/test/benchmark.c
+++ b/programs/test/benchmark.c
@@ -100,7 +100,7 @@
"md4, md5, ripemd160, sha1, sha256, sha512,\n" \
"arc4, des3, des, camellia, blowfish,\n" \
"aes_cbc, aes_gcm, aes_ccm, aes_cmac, aes_xts,\n" \
- "des3_cmac, havege, ctr_drbg, hmac_drbg\n" \
+ "des3_cmac, havege, ctr_drbg, hmac_drbg,\n" \
"rsa, dhm, ecdsa, ecdh.\n"
#if defined(MBEDTLS_ERROR_C)