Try to convince Coverity this string is terminated.

src/persist_read_v234.c

@@ -180,9 +180,9 @@ int persist__chunk_msg_store_read_v234(FILE *db_fptr, struct P_msg_store *chunk,
 			log__printf(NULL, MOSQ_LOG_ERR, "Error: Out of memory.");
 			return MOSQ_ERR_NOMEM;
 		}
+		read_e(db_fptr, chunk->payload, chunk->F.payloadlen);
 		/* Ensure zero terminated regardless of contents */
 		((uint8_t *)chunk->payload)[chunk->F.payloadlen] = 0;
-		read_e(db_fptr, chunk->payload, chunk->F.payloadlen);
 	}
 
 	return MOSQ_ERR_SUCCESS;

src/persist_read_v5.c

@@ -203,9 +203,9 @@ int persist__chunk_msg_store_read_v56(FILE *db_fptr, struct P_msg_store *chunk,
 			log__printf(NULL, MOSQ_LOG_ERR, "Error: Out of memory.");
 			return MOSQ_ERR_NOMEM;
 		}
+		read_e(db_fptr, chunk->payload, chunk->F.payloadlen);
 		/* Ensure zero terminated regardless of contents */
 		((uint8_t *)chunk->payload)[chunk->F.payloadlen] = 0;
-		read_e(db_fptr, chunk->payload, chunk->F.payloadlen);
 	}
 
 	if(length > 0){