tools lib subcmd: Make it an error to pass a signed value to OPTION_UINTEGER

Options marked OPTION_UINTEGER or OPTION_U64 clearly indicates that an
unsigned value is expected, so just error out when a negative value is
passed, instead of returning something undesired to the tool.

E.g.:

  # 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
  #

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-2mdn8s2raatyhz7tamrsz22r@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/subcmd/parse-options.c

@@ -270,6 +270,8 @@ static int get_value(struct parse_opt_ctx_t *p,
 		}
 		if (get_arg(p, opt, flags, &arg))
 			return -1;
+		if (arg[0] == '-')
+			return opterror(opt, "expects an unsigned numerical value", flags);
 		*(unsigned int *)opt->value = strtol(arg, (char **)&s, 10);
 		if (*s)
 			return opterror(opt, "expects a numerical value", flags);
@@ -302,6 +304,8 @@ static int get_value(struct parse_opt_ctx_t *p,
 		}
 		if (get_arg(p, opt, flags, &arg))
 			return -1;
+		if (arg[0] == '-')
+			return opterror(opt, "expects an unsigned numerical value", flags);
 		*(u64 *)opt->value = strtoull(arg, (char **)&s, 10);
 		if (*s)
 			return opterror(opt, "expects a numerical value", flags);