jitterentropy: Include <fcntl.h> and <limits.h>
* random/jitterentropy-base-user.h: Include <fcntl.h> for O_RDONLY * random/jitterentropy-base-user.h: Include <limits.h> for LONG_MAX
Fixes the build with musl libc.
- Signed-off-by: Heiko Becker <heirecka@exherbo.org>