fix missing va_end #86

Job	Run time
Dockerfile-repo-root	4m 29s
Dockerfile_openexr3-repo-root	6m 42s
fedora-36	2m 53s
fedora-37	2m 39s
redhat-ubi9	5m 18s
redhat-ubi8	4m 41s
ubuntu-18-04	1m 27s
ubuntu-20-04	1m 47s
ubuntu-22-04	1m 23s
ubuntu-22-04-LTO	2m 13s
ubuntu-latest	1m 54s
fedora-38	3m 21s
fedora-latest	2m 45s
ubuntu-openexr2-shared	2m 51s
ubuntu-22-04-openexr33	3m 49s
ubuntu-openexr2-static	2m 49s
	51m 1s

Provide feedback