Fixes build with musl: | ../git/src/shared/dissect-image.c: In function 'mount_image_privately_interactively': | ../git/src/shared/dissect-image.c:2986:34: error: 'LOCK_SH' undeclared (first use in this function) | 2986 | r = loop_device_flock(d, LOCK_SH); | | ^~~~~~~