btf: report correct method in TestTypeByName fatal message
btf: report correct method in TestTypeByName fatal message

FindType was renamed to TypeByName in commit 9b2180471cfe ("btf: rename
FindType to TypeByName, add AnyTypesByName and TypeByID methods").
Adjust the fatal message in TestTypeByName accordingly.

Signed-off-by: Tobias Klauser <059b8b880f8441509ec8a65b50b4c6ae74ebea76@cilium.io>

cilium/ebpf,cilium/ebpf