Upgrade Firecracker to v0.21.0

kzys · kzys · commit 8c6d72548f95 · 2020-02-19T08:40:00.000-08:00
Signed-off-by: Kazuyoshi Kato &lt;katokazu@amazon.com&gt;
diff --git a/_submodules/firecracker b/_submodules/firecracker
@@ -1 +1 @@
-Subproject commit 57ac9df0ad1260adcb1c8c53924aa4c094453ffd
+Subproject commit 6fd1545222f4f5e01dc3968da819276500296380
