driver/shelldriver: handle existing /tmp/labgrid-ssh/ gracefully

When activating -> deactivating -> activating a ShellDriver or forcing a
strategy shell state that put an SSH key on the target in a prior run,
mkdir fails because the directory already exists. That should not be an
error, so add `-p` to the mkdir invocation.

Signed-off-by: Bastian Krause <bst@pengutronix.de>

Author: Bastian-Krause

labgrid/driver/shelldriver.py

@@ -275,7 +275,7 @@ def _put_ssh_key(self, keyfile_path):
             return
 
         self.logger.debug("Key not on target and not writeable, using bind mount...")
-        self._run_check('mkdir -m 700 /tmp/labgrid-ssh/')
+        self._run_check('mkdir -p -m 700 /tmp/labgrid-ssh/')
         self._run("cp -a ~/.ssh/* /tmp/labgrid-ssh/")
         self._write_key(keyline, "/tmp/labgrid-ssh/authorized_keys")
         self._run_check('chmod 600 /tmp/labgrid-ssh/authorized_keys')