nss-resolve: report ERANGE for small buffers. (#5359)

nss-resolve: report ERANGE for small buffers. (#5359)

The correct error code to report when a provided buffer is too small is
ERANGE. This is recognized by glibc, which will then try again with a
larger buffer. The old behaviour of reporting ENOMEM has no special
meaning for glibc. The error will simply be propagated to the
application, and a later retry will trigger the same error again.

Additionally, h_errnop must be set to NETDB_INTERNAL to have glibc look
at errnop for details.

More information at:
https://www.gnu.org/software/libc/manual/html_node/NSS-Modules-Interface.html