run-docker: don't raise if sh exit status != 0, forward to host instead

run-docker

@@ -2,6 +2,7 @@
 
 import argparse
 import os
+import sys
 
 import common
 import shell_helpers
@@ -41,11 +42,13 @@ def sh_func(args):
         sh_args = args
     else:
         sh_args = ['bash']
-    sh.run_cmd(
+    exit_status = sh.run_cmd(
         docker + ['exec', '-i', '-t', container_name] +
         sh_args +
         [LF],
+        raise_on_failure=False
     )
+    sys.exit(exit_status)
 def start(args):
     sh.run_cmd(docker + ['start', container_name, LF])
 def stop(args):