Avoid implementation-defined behavior

On platforms where 'int' is 32 bits, shifting an 'int' by 31 bits
is implementation-defined behavior.  While our toolchain is almost
certainly doing what we expect here, we switch to shifting an
unsigned to assure it always does the right thing.

Test: TreeHugger
Change-Id: Ied2b5c98a27a43e091bf5819d1b37cc7b43b2906
1 file changed