arte to mwl extraction warning

[hsw28]

When trying to build arte to mwl extract using the build file here: https://github.com/hsw28/arte-backend/tree/master/src/extract I receive the warning

hannah@rat4vis:~/Programming/arte-backend/src/extract$ ./build.sh
arte_to_mwl.cpp: In function ‘void write_file_header(void*, int, char**, packetType_t)’:
arte_to_mwl.cpp:310:40: warning: too many arguments for format [-Wformat-extra-args]
     lfp->n_chans, lfp->n_samps_per_chan);

It still compiles and creates an executable with the warning.