fix fuzz targets (#5851)
fix fuzz targets (#5851)

Signed-off-by: Krzysztof Kowalczyk <01efde20626170fe1b962a658b84a1b814ce74a8@gmail.com>
prometheus/prometheus,alileza/prometheus,alileza/prometheus,keegancsmith/prometheus,alileza/prometheus,alileza/prometheus,kangwoo/prometheus,GoogleCloudPlatform/prometheus,Gouthamve/prometheus,Gouthamve/prometheus,kangwoo/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,alileza/prometheus,kangwoo/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,GoogleCloudPlatform/prometheus,kangwoo/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,Gouthamve/prometheus,prometheus/prometheus,prometheus/prometheus,prometheus/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus