test-lib: avoid full path to store test results

No reason to use the full path in case this is used externally.

Otherwise we might get errors such as:

./test-lib.sh: line 394: /home/bob/dev/git/t/test-results//home/bob/dev/git/contrib/remote-hg/test-2894.counts: No such file or directory

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>

t/test-lib.sh

@@ -389,7 +389,8 @@ test_done () {
 	then
 		test_results_dir="$TEST_OUTPUT_DIRECTORY/test-results"
 		mkdir -p "$test_results_dir"
-		test_results_path="$test_results_dir/${0%.sh}-$$.counts"
+		base=${0##*/}
+		test_results_path="$test_results_dir/${base%.sh}-$$.counts"
 
 		cat >>"$test_results_path" <<-EOF
 		total $test_count