tools/lib/subcmd/pager.c: do not alias select() params

tools/lib/subcmd/pager.c: do not alias select() params

Use a separate fd set for select()-s exception fds param to fix the
following gcc warning:

  pager.c:36:12: error: passing argument 2 to restrict-qualified parameter aliases with argument 4 [-Werror=restrict]
    select(1, &in, NULL, &in, NULL);
              ^~~        ~~~

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>