oe.path.realpath() provides are common and more correct implementation
for resolving symlinks within sysroot. Use it.
Old implementation suffered from lot of problems; e.g.
* redundant code
* calls 'os.stat()' which references files on host; this can give wrong
results about existing/non-existing and can cause EPERM (instead of
the catched ENONENT) exceptions
* does not deal with special cases like '..' leaving the sysroot.
Signed-off-by: Enrico Scholz <enrico.scholz@sigma-chemnitz.de> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
