t/test-lib.sh: drop "$test" variable

The $test variable is used as an interim buffer for
constructing $TRASH_DIRECTORY, and is almost compatible with
it (the exception being that $test has not been converted to
an absolute path). Let's get rid of it entirely so that
later code does not accidentally use it, thinking the two
are interchangeable.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

t/test-lib.sh

@@ -592,11 +592,11 @@ then
 fi
 
 # Test repository
-test="trash directory.$(basename "$0" .sh)"
-test -n "$root" && test="$root/$test"
-case "$test" in
-/*) TRASH_DIRECTORY="$test" ;;
- *) TRASH_DIRECTORY="$TEST_OUTPUT_DIRECTORY/$test" ;;
+TRASH_DIRECTORY="trash directory.$(basename "$0" .sh)"
+test -n "$root" && TRASH_DIRECTORY="$root/$TRASH_DIRECTORY"
+case "$TRASH_DIRECTORY" in
+/*) ;; # absolute path is good
+ *) TRASH_DIRECTORY="$TEST_OUTPUT_DIRECTORY/$TRASH_DIRECTORY" ;;
 esac
 test ! -z "$debug" || remove_trash=$TRASH_DIRECTORY
 rm -fr "$TRASH_DIRECTORY" || {