Inconsistent use of OPENSSL_CFLAGS & OPENSSL_LIBS in the build system

[rgmiller]

System information

Type	Version/Name
Operating System	Linux
OS Version	Ubuntu 22.04
Architecture	x86_64
UnifyFS Version	git dev branch

Describe the problem you're observing

We are not consistent in our use of the OPENSSL_CFLAGS and OPENSSL_LIBS in our build system. Specifically, the configure script will set these variables in all the Makefiles, but only the Makefile for unifyfs-stage will actually use these variables. The practical upshot is that unifyfs-stage may end up being linked against a different version of libcrypto.

It's also noteworthy that if you're trying to use a non-default version of libcrypto (such as a version built by spack), unifyfs-stage will be the only part of UnifyFS that uses the requested version.

This is tangentially related to issue #723 and PR #791. Also note that these variable names might change as part of PR #791.

Describe how to reproduce the problem

To really see this, you probably want 2 versions of OpenSSL installed. (Having a spack-built version and a system-provided version is probably the easiest way to arrange this.) Then, after building UnifyFS, run ldd on unifyfs and unifyfs-stage. You should see that they link against two different versions of libcrypto.

Include any warning or errors or releveant debugging data

[CamStan]

Adding OpenSSL package for reference: https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/openssl/package.py