Logging: rework printing to file descriptor to be cross-platform. (v)snprintf() is now used to build the log message, and write() to then write it directly to the file descriptor.
Logging: rework printing to file descriptor to be cross-platform. (v)snprintf() is now used to build the log
message, and write() to then write it directly to the file descriptor.

inilabs/libcaer,inilabs/libcaer,inilabs/libcaer,inilabs/libcaer