ovl: do not set overlay.opaque on non-dir create

ovl: do not set overlay.opaque on non-dir create

BugLink: http://bugs.launchpad.net/bugs/1692898
commit 4a99f3c83dc493c8ea84693d78cd792839c8aa64 upstream.

The optimization for opaque dir create was wrongly being applied
also to non-dir create.

Fixes: 97c684cc9110 ("ovl: create directories inside merged parent opaque")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>