crosvm: Supress unused mut warning for variable linux in run_vm
crosvm: Supress unused mut warning for variable linux in run_vm

BUG=None
TEST=emerge-${BOARD} crosvm

Change-Id: Ib1e3629a7df98dd5a87955565757bb8ba96bdf87
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2825629
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Tested-by: Kuo-Hsin Yang <a2fdcd08c01d5cc005d409dc015bd79e7faa561f@chromium.org>
Reviewed-by: Chirantan Ekbote <35787c0e27de5c48735e07f8324823b765e8bcbc@chromium.org>
Commit-Queue: Kuo-Hsin Yang <a2fdcd08c01d5cc005d409dc015bd79e7faa561f@chromium.org>

google/crosvm,google/crosvm,google/crosvm,google/crosvm