ocb3: don't zero ocb3 context in ocb3_{de,en}crypt_last

src/encauth/ocb3/ocb3_decrypt_last.c

@@ -93,7 +93,6 @@ LBL_ERR:
 #ifdef LTC_CLEAN_STACK
    zeromem(iOffset_star, MAXBLOCKSIZE);
    zeromem(iPad, MAXBLOCKSIZE);
-   zeromem(ocb, sizeof(*ocb));
 #endif
 
    return err;

src/encauth/ocb3/ocb3_encrypt_last.c

@@ -95,7 +95,6 @@ LBL_ERR:
 #ifdef LTC_CLEAN_STACK
    zeromem(iOffset_star, MAXBLOCKSIZE);
    zeromem(iPad, MAXBLOCKSIZE);
-   zeromem(ocb, sizeof(*ocb));
 #endif
 
    return err;