ncdump -s fails on UDF files with "Unrecognized format" error

[captainkirk99]

When ncdump -s tries to print out the format of a file opened with User Defined Formats (as is done by the NetCDF Expansion Pack), it fails with "Unrecognized format" error.

For example:

netcdf ABBA_2022_C61_HNL {
dimensions:
        x = 55877 ;
        y = 41013 ;
        bnds = 2 ;
variables:
        ubyte data(y, x) ;
                data:_Storage = "contiguous" ;
        ...
// global attributes:
ncdump: unrecognized file format: 9

This is a simple fix, however testing was a pain.

I will have a PR up with a fix shortly...