docs/updating_clang.md: update try job commands

Updates some commands to run try jobs that have moved to LUCI, and
adds linux_chromium_chromeos_msan_rel_ng.

Change-Id: I9048da9f6dcb897b5125183d3f66b5995e740de8
Reviewed-on: https://chromium-review.googlesource.com/1112347
Commit-Queue: Bob Haarman <inglorion@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569749}

docs/updating_clang.md

@@ -35,12 +35,11 @@
     ```shell
     git cl try &&
     git cl try -m tryserver.chromium.mac -b mac_chromium_asan_rel_ng &&
-    git cl try -B luci.chromium.try -b ios-device &&
-    git cl try -m tryserver.chromium.linux \
-      -b linux_chromium_chromeos_asan_rel_ng -b linux_chromium_msan_rel_ng \
-      -b linux_chromium_cfi_rel_ng &&
+    git cl try -m tryserver.chromium.linux -b linux_chromium_cfi_rel_ng &&
     git cl try -m tryserver.blink -b linux_trusty_blink_rel &&
-    git cl try -m luci.chromium.try -b linux-chromeos-dbg
+    git cl try -B luci.chromium.try -b ios-device \
+      -b linux_chromium_chromeos_asan_rel_ng -b linux_chromium_msan_rel_ng \
+      -b linux_chromium_chromeos_msan_rel_ng -b linux-chromeos-dbg
     ```
 
 1.  Start Pinpoint perf tryjobs. These are generally too noisy to catch minor