Remove a warning when $HOME is on NFS

If ~/.subversion doesn't exist, the code didn't run, but if it existed
there is no reason to re-create it, nor is it necessary to change its
permissions since they are inherited by the bind mount source.
However user_mkdir was trying to run chown as root which does not work
over NFS with root_squash or krb-nfs.
Therefore, the un-needed call to user_mkdir is removed.
(this is an issue because cros_sdk  --replace does call this code path
multiple times).

BUG=None
TEST=Built the chroot, and the permission denied on 'install' went away.
Change-Id: I01e9a7baf51a99a96d790c9613e26e652379e6df
Reviewed-on: https://gerrit.chromium.org/gerrit/44880
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Marc MERLIN <merlin@chromium.org>
Tested-by: Marc MERLIN <merlin@chromium.org>
diff --git a/sdk_lib/enter_chroot.sh b/sdk_lib/enter_chroot.sh
index e582d42..20127ad 100755
--- a/sdk_lib/enter_chroot.sh
+++ b/sdk_lib/enter_chroot.sh
@@ -314,9 +314,8 @@
       fi
     fi
 
-    if [ -d "$SUDO_HOME/.subversion" ]; then
+    if [[ -d "$SUDO_HOME/.subversion" ]]; then
       TARGET="/home/${SUDO_USER}/.subversion"
-      user_mkdir "${FLAGS_chroot}${TARGET}"
       setup_mount "${SUDO_HOME}/.subversion" "--bind" "${TARGET}"
       # Symbolic-link the .subversion directory so sandboxed subversion.class
       # clients can use it.