USB: ums_realtek: do not use stack memory for DMA in __do_config_autodelink

commit 4898e07174b79013afd2b422ef6c4336ef8e6783 upstream.

__do_config_autodelink passes the data variable to the transport function.
If the calling functions pass a stack variable, this will eventually trigger
a DMA-API debug backtrace for mapping stack memory in the DMA buffer.  Fix
this by calling kmemdup for the passed data instead.

Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>