Add security fuzzy tests and improve pyocf api

Fuzzy tests added for:
changing cache mode
attaching cache device with fuzzed cache line size
setting cleaning policy
setting alru params
setting acp params
setting seq cut off policy per cache
setting seq cut off policy per core

tests/functional/pyocf/utils.py

@@ -15,7 +15,6 @@ def print_buffer(buf, length, offset=0, width=16, stop_after_zeros=0):
 
     for addr in range(offset, end, width):
         cur_line = buf[addr : min(end, addr + width)]
-        all_zeros = True
         byteline = ""
         asciiline = ""
         if not any(cur_line):