Revert "perf bench futex: Sanitize numeric parameters"

Revert "perf bench futex: Sanitize numeric parameters"

This reverts commit 60758d6668b3e2fa8e5fd143d24d0425203d007e.

Now that libsubcmd makes sure that OPT_UINTEGER options will not
return negative values, we can revert this patch while addressing
the problem it solved:

  # perf bench futex hash -t  -4
  # Running 'futex/hash' benchmark:
   Error: switch `t' expects an unsigned numerical value
   Usage: perf bench futex hash <options>

      -t, --threads <n>     Specify amount of threads
  # perf bench futex hash -t-4
  # Running 'futex/hash' benchmark:
   Error: switch `t' expects an unsigned numerical value
   Usage: perf bench futex hash <options>

      -t, --threads <n>     Specify amount of threads
  #

IMO it is more reasonable to flat out refuse to process a negative
number than to silently turn it into an absolute value.

This also helps in silencing clang's complaint about asking for an
absolute value of an unsigned integer:

  bench/futex-hash.c:133:10: error: taking the absolute value of unsigned type 'unsigned int' has no effect [-Werror,-Wabsolute-value]
          nsecs = futexbench_sanitize_numeric(nsecs);
                ^
  bench/futex.h:104:42: note: expanded from macro 'futexbench_sanitize_numeric'
  #define futexbench_sanitize_numeric(__n) abs((__n))
                                           ^
  bench/futex-hash.c:133:10: note: remove the call to 'abs' since unsigned values cannot be negative

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2kl68v22or31vw643m2exz8x@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>