Rewind logic was not supporting count = 1, where size was > memif_buffer_size and a rewind is required.
Fixed slot-->next_buf bug for !master as well.
Type: fix
Change-Id: I65cf0d3d0c105f37125412a613e5ff8c5da9a3a2
Signed-off-by: mbly <mbly@ciena.com>