test_wildcard() was never executed: run_testcases() only picks up
functions named testcase_* so this test never ran. This commmit
makes it run and fixes two issues in the test:
1. /etc/hostname is absent in the test image so we need to guard
for that.
2. The pattern check was written as [[ "$P" == "$H" ]] with both
sides quoted, but we need to one side unquoted as otherwise
the comparison will always be false.
Michael Vogt
aa0f05173b