test/make: update source abi dir path

Update reference build path to latest build.
Change path to use a generic directory name instead
of using specific SPDK version in the name. That way
in future we can update the build just after the
release, and still make ABI checks for patches which
were not rebased.

Signed-off-by: Karol Latecki <karol.latecki@intel.com>
Change-Id: I32850a871274773e334057b60b9df238ef85a999
Signed-off-by: Karol Latecki <karol.latecki@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/3532


Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Community-CI: Mellanox Build Bot