lpdump: Use unsigned value for shift

Shifting a signed 32-bit value by 31 bits is implementation-defined
behavior.  While our toolchains are most probably doing the
expected thing, we make this an unsigned value out of paranoia.

Test: TreeHugger
Change-Id: I551fcf1ac7a27ebd7c1365cd6a9df7267f569c44
1 file changed