[ Upstream commit 61cd1b4c ]

ds2490 driver was doing USB transfers from / to buffers on a stack.
This is not permitted and made the driver non-working with vmapped stacks.

Since all these transfers are done under the same bus_mutex lock we can
simply use shared buffers in a device private structure for two most common
of them.

While we are at it, let's also fix a comparison between int and size_t in
ds9490r_search() which made the driver spin in this function if state
register get requests were failing.
Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Cc: stable <stable@vger.kernel.org>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>