cxgb4: silence shift wrapping static checker warning
cxgb4: silence shift wrapping static checker warning

I don't know how large "tp->vlan_shift" is but static checkers worry
about shift wrapping bugs here.

Signed-off-by: Dan Carpenter <ff341aa343d564f9e53e9dcb6996be8c04859a66@oracle.com>
Acked-by: Dimitris Michailidis <8f489e765add66cea532ca1aff150e01610199e3@chelsio.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs