test.sh: fix removal of test output files

test.sh

@@ -35,7 +35,7 @@ for n in $(seq 1 25); do
 		echo -n "$solution... "
 
 		solution_output=$(mktemp)
-		trap 'rm $solution_output' EXIT
+		trap "rm -f '$solution_output'" EXIT
 
 		run_solution "$solution" > "$solution_output"
 
@@ -53,5 +53,7 @@ for n in $(seq 1 25); do
 		else
 			echo ok
 		fi
+
+		rm "$solution_output"
 	done
 done