Per bug #66551, remove all HMAC_ calls from exported symbol list. All

HMAC_ functionality can be done the PKCS#11 interface.

security/nss/lib/nss/nss.def

@@ -283,11 +283,6 @@ CERT_VerifyCert;
 DER_GetInteger;
 DER_TimeToUTCTime;
 DER_UTCTimeToTime;
-HMAC_Begin;
-HMAC_Create;
-HMAC_Destroy;
-HMAC_Finish;
-HMAC_Update;
 PBE_CreateContext;
 PBE_DestroyContext;
 PBE_GenerateBits;