pocsense: fix infinite loop in linop_wavelet_create
pocsense: fix infinite loop in linop_wavelet_create

The previous code  would lead to in infinite loop in
`wavelet_num_levels`.
This code builds both the flags and minsize correctly.

sidward/bart,mrirecon/bart,mrirecon/bart,sidward/bart,sidward/bart,mrirecon/bart,sidward/bart,mrirecon/bart,mrirecon/bart,sidward/bart