Fix paths that were trying to go above the root by using too many "../.."

This doesn't cause problems because seems like GN just ignores these attempts and confines everything to the root.

Bug: None
Change-Id: Ief50b6e10f3950b319d0bde547f91dcc7f237cda
Reviewed-on: https://webrtc-review.googlesource.com/90041
Commit-Queue: Oleh Prypin <oprypin@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24063}

logging/BUILD.gn

@@ -439,7 +439,7 @@ if (rtc_include_tests) {
     ]
     deps = [
       ":rtc_event_log_api",
-      "../../test:test_support",
+      "../test:test_support",
     ]
   }
 }