Fix wrong bitmap output for cluster raid

Fix wrong bitmap output for cluster raid

For cluster raid, we need to displays bitmap related
contents from different bitmaps which are based on node
num. So bitmap_file_open and locate_bitmap are changed a
little bit for the purpose.

Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Fixes: b98043a2f8 ("Show all bitmaps while examining bitmap")
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>