net: dev: Use unsigned integer as an argument to left-shift

[ Upstream commit f4d7b3e23d259c44f1f1c39645450680fcd935d6 ]

1 << 31 is Undefined Behaviour according to the C standard.
Use U type modifier to avoid theoretical overflow.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>