kill: Correct pid type

Previous commit used a pid type of int in the printf, this should
be a long.

References:
 commit 5e9c522eea

kill.c

@@ -132,7 +132,7 @@ int main(int argc, char **argv)
         pid = strtol_or_err(argv[i], _("failed to parse argument"));
         if (!kill((pid_t) pid, signo))
             continue;
-        error(0, errno, "(%d)", pid);
+        error(0, errno, "(%ld)", pid);
         exitvalue = EXIT_FAILURE;
         continue;
     }