bsc CBSP: f_page2rsl(): allow expecting specific nr of blocks

Subsequent patch I3cace19f9e5adc8ebab13ef2328a36dc150b2b31 adds a test with
specific payload lengths. To verify the correctness of the number-of-blocks
calculation (recently fixed), allow pinpointing the expected blocks count.

Change-Id: Ie58a6175e55ab2679dc69f9e191d0efc0e84cde0
1 file changed