staging: gasket: core: remove debug log that could crash

A debug log in gasket_alloc_dev() is issued regardless of whether the
device pointer used returned success or error.  The log isn't that
useful anyway, remove it.

Signed-off-by: Todd Poynor <toddpoynor@google.com>
Reviewed-by: Rob Springer <rspringer@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>