Revert "Update clang linux to release_40"

This reverts commit a08104abf2850546d97c5d33f5fb5fabedf45466.

Reason for revert: MSAN's failing immediately, and ASAN is catching a new leak:

==20306==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 4112 byte(s) in 257 object(s) allocated from:
    #0 0x138828b  (/b/s/w/irNps76D/out/Release/dm+0x138828b)
    #1 0x2c07b76  (/b/s/w/irNps76D/out/Release/dm+0x2c07b76)



Original change's description:
> Update clang linux to release_40
> 
> Bug: skia:
> Change-Id: Ibe2406592024a4eb20b278ad189d3abddec129d9
> Reviewed-on: https://skia-review.googlesource.com/11285
> Reviewed-by: Mike Klein <mtklein@chromium.org>
> Commit-Queue: Mike Klein <mtklein@chromium.org>
> 

TBR=mtklein@chromium.org,mtklein@google.com,kjlubick@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I178c129cf19ed38f0a91ea3eea583643daadc2c7
Reviewed-on: https://skia-review.googlesource.com/11288
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
3 files changed