Disable system_health.memory_desktop.multitab:misc:typical24 on Linux

TBR=charliea@chromium.org
NOTRY=true  # test covered by CQ

Bug: 838504
Change-Id: I8ec5666a5b15df157ec552f06c1504a3592ef482
Reviewed-on: https://chromium-review.googlesource.com/1057954Reviewed-by: Ned Nguyen <nednguyen@google.com>
Commit-Queue: Ned Nguyen <nednguyen@google.com>
Cr-Commit-Position: refs/heads/master@{#558370}

tools/perf/expectations.config

@@ -285,6 +285,7 @@ crbug.com/676336 [ Mac ] system_health.memory_desktop/browse:news:hackernews [ S
 crbug.com/649392 [ Win ] system_health.memory_desktop/play:media:soundcloud [ Skip ]
 crbug.com/649392 [ All ] system_health.memory_desktop/play:media:google_play_music [ Skip ]
 crbug.com/742475 [ Mac ] system_health.memory_desktop/multitab:misc:typical24 [ Skip ]
+crbug.com/838504 [ Linux ] system_health.memory_desktop/multitab:misc:typical24 [ Skip ]
 crbug.com/773084 [ Mac ] system_health.memory_desktop/browse:tools:maps [ Skip ]
 crbug.com/769809 [ All ] system_health.memory_desktop/browse_accessibility:tools:gmail_compose [ Skip ]
 crbug.com/673775 [ Win ] system_health.memory_desktop/browse:search:google [ Skip ]