err: fix crash in ERR_load_strings() when configured with no-err

err: fix crash in ERR_load_strings() when configured with no-err

This commit removes the entire initialization and cleanup of the
error string hash table (`int_error_hash`) if `no-err` is configured.
The only operative function remaining is `ERR_get_next_error_library()`.
That is the reason why the `err_string_lock` and hence the
`do_err_strings_init()` function can't be removed entirely.

Fixes #17971

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/17974)