enter_chroot: ignore errors from copying user ssh files

The current code that syncs the user's ssh files from ~/.ssh/ to the
chroot assumes the user has these files in the first place.  For the
fresh user and/or install, these might not exist.  So ignore errors
from attempting to copy them.  It's not like we attempt to "recover"
anyways, and this sync is more of a "let's make things smoother" than
a "we need this to run properly".

BUG=chromium-os:15005
TEST=`mv ~/.ssh ~/.ssh.bak; mkdir ~/.ssh; cros_sdk` and see no more warnings

Change-Id: I9cac2ecad7c64c088fbdfe55377c0429b3b7ab03
Reviewed-on: https://gerrit.chromium.org/gerrit/10922
Reviewed-by: David James <davidjames@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Ready: Mike Frysinger <vapier@chromium.org>
diff --git a/sdk_lib/enter_chroot.sh b/sdk_lib/enter_chroot.sh
index 3fb61d7..377e565 100755
--- a/sdk_lib/enter_chroot.sh
+++ b/sdk_lib/enter_chroot.sh
@@ -254,7 +254,8 @@
       if [ -n "${SSH_AUTH_SOCK}" -a -d "${HOME}/.ssh" ]; then
         TARGET_DIR="${FLAGS_chroot}/home/${USER}/.ssh"
         mkdir -p "${TARGET_DIR}"
-        cp "${HOME}"/.ssh/{known_hosts,*.pub} "${TARGET_DIR}/"
+        # Ignore errors as some people won't have these files to copy.
+        cp "${HOME}"/.ssh/{known_hosts,*.pub} "${TARGET_DIR}/" 2>/dev/null || :
         copy_ssh_config "${TARGET_DIR}"
         ASOCK=${SSH_AUTH_SOCK%/*}
         ensure_mounted "${ASOCK}" "--bind" "${ASOCK}"