Add the minimum and maximum matching DLTs to an error message.

Add the minimum and maximum matching DLTs to an error message.

This is to try to figure out why some NetBSD CI builds are failing - a
change that *shouldn't* have affected this causes "make check" to fail
on the switch-header capture files, claiing that the switch-header DLT_
values are unknown.

(Is the libpap compile picking up the system pcap/dlt.h rather than the
pcap/dlt.h in the source tree, and thus getting an old version of
DLT_MATCHING_MAX from before the addition of those link-layer types?)