tools: Copy linux/{hash,poison}.h and check for drift

tools: Copy linux/{hash,poison}.h and check for drift

We were also using this directly from the kernel sources, the two last
cases, fix it.

Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>