build: handle usrmerge

When building for merged-usr systems, the location of libdir might
be in `/usr/lib`.  We should rely on the passed in `${libdir}` for
installation rather than hard-coding as `/lib/security`

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: If53ea402f1e50416bc8a0e561d42080ea68742f9
1 file changed