libhandle: fix installation for symlinked /usr

libhandle: fix installation for symlinked /usr

Canonicalize the pathnames for PKG_LIB_DIR and PKG_ROOT_LIB_DIR
before checking if they are the same.  This is required for Fedora
which doesn't have a separate /usr/lib directory anymore.

[Christoph Hellwig: reformat and change to canonical names]

Reported-by: Jan Tulak <jan@tulak.me>
Signed-off-by: Jan Tulak <jan@tulak.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>