tests: avoid spurious failure of 'uninstall-fail.test' on Solaris * tests/uninstall-fail.test: All the Solaris 10 shells (/bin/sh, /bin/ksh, and /usr/xpg4/bin/sh), upon failing to chdir to a directory with the `cd' builtin, print a message like: "sh: /root: permission denied" which doesn't report the `cd' builtin anywhere. Relax the grepping of the error message accordingly.