memory leak in g2_getfld() if errors occur reading message

[edwardhartnett]

In g2_getfld() we have:

lgfld = malloc(sizeof(gribfield));
Later in the code:

    if (istart == -1) {
        printf("g2_getfld:  Beginning characters GRIB not found.\n");
        ierr = 1;
        return(ierr);
    }

and

    if (istart == -1) {
        printf("g2_getfld:  Beginning characters GRIB not found.\n");
        ierr = 1;
        return(ierr);
    }

and

    /*  Currently handles only GRIB Edition 2. */
    if (ver != 2) {
        printf("g2_getfld: can only decode GRIB edition 2.\n");
        ierr = 2;
        return(ierr);
    }

and there are some other returns for error conditions. Note that they are not freeing the memory allocated in lgfld. There are (commented out) tests for this in tst_g2_addfield.c.