* coverity fixes
cmdhflegic- indications are the i in calls to data_buf[i] could = 1052
and overflow the array.
cmdhfmfhard - +1 to add space for string null terminator - should we add
the 0 terminator value too?
reveng.c - memory leak
util.c - fix potential overflow of array buf[]
util_posix.c - possible integer overflow
* fix help errors
* fix sprint_hex_ascii
again
and this function is not even used anywhere... yet...
add parameter for # bits to read
auto get samples after lf read/snoop (don't need to do a `data samples`
anymore)
add safe function to get DemodBuffer
add some lf demod comments and apply new lf_read function instead of
read then get samples.
fixed output bug in lf t55xx config print
fixed small bug in lf t55xx detect during ST check
