ar, ranlib: Don't double close file descriptors

ar, ranlib: Don't double close file descriptors

Found by GCC14 -Wanalyzer-fd-double-close.

close always closes the given file descriptor even on error. So don't
try to close a file descriptor again on error (even on EINTR). This
could be bad in a multi-threaded environment.

      * src/ar.c (do_oper_extract): Call close and set newfd to -1.
      (do_oper_delete): Likewise.
      (do_oper_insert): Likewise.
      * src/ranlib.c (handle_file): Likewise.

Signed-off-by: Mark Wielaard <mark@klomp.org>