This reverts commit 5c1de006.

While the original commit makes it easier to run cpupower from the
local build directory, it also leaves the binary with a rather poor
rpath of './' in it after it is installed on a system via 'make install'.

This is considered bad practice and can cause cpupower to fail in
rpmbuild with the following error:

ERROR   0004: file '/usr/bin/cpupower' contains an insecure rpath './' in [./]
error: Bad exit status from /var/tmp/rpm-tmp.A6u26r (%install)
    Bad exit status from /var/tmp/rpm-tmp.A6u26r (%install)

Developers should be able to use LD_LIBRARY_PATH to achieve the same
effect and not introduce rpath into the binary.

Signed-off-by: Josh Boyer <jwboyer@feoraproject.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>