Fix json output test

Author: djrenren

src/test/run-make-fulldeps/libtest-json/output.json

@@ -1,10 +1,10 @@
 { "type": "suite", "event": "started", "test_count": "4" }
-{ "type": "test", "event": "started", "name": "a" }
-{ "type": "test", "name": "a", "event": "ok" }
-{ "type": "test", "event": "started", "name": "b" }
-{ "type": "test", "name": "b", "event": "failed", "stdout": "thread 'b' panicked at 'assertion failed: false', f.rs:18:5\nnote: Run with `RUST_BACKTRACE=1` for a backtrace.\n" }
-{ "type": "test", "event": "started", "name": "c" }
-{ "type": "test", "name": "c", "event": "ok" }
-{ "type": "test", "event": "started", "name": "d" }
-{ "type": "test", "name": "d", "event": "ignored" }
+{ "type": "test", "event": "started", "name": "f::a" }
+{ "type": "test", "name": "f::a", "event": "ok" }
+{ "type": "test", "event": "started", "name": "f::b" }
+{ "type": "test", "name": "f::b", "event": "failed", "stdout": "thread 'f::b' panicked at 'assertion failed: false', f.rs:18:5\nnote: Run with `RUST_BACKTRACE=1` for a backtrace.\n" }
+{ "type": "test", "event": "started", "name": "f::c" }
+{ "type": "test", "name": "f::c", "event": "ok" }
+{ "type": "test", "event": "started", "name": "f::d" }
+{ "type": "test", "name": "f::d", "event": "ignored" }
 { "type": "suite", "event": "failed", "passed": 2, "failed": 1, "allowed_fail": 0, "ignored": 1, "measured": 0, "filtered_out": "0" }