fix(devtool): exit with error if firecracker fails to build

way too often have I accidentally ran an out dated firecracker binary
when testing something because a change I made doesnt compile, but the
failure to build firecracker wasn't considered fatal by devtool, and the
sheer amount of stuff it prints after compiling pushed the compiler
error offscreen.

Fix this by exiting if firecracker fails to build.

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

tools/devtool

@@ -723,6 +723,7 @@ cmd_test() {
       cmd_build --release
       if [ -n "$BUILDKITE_PULL_REQUEST_BASE_BRANCH" ]; then
         cmd_build --release --rev "$BUILDKITE_PULL_REQUEST_BASE_BRANCH"
+        ok_or_die "Failed to build Firecracker!"
       fi
     fi