Instead of downloading this repository, one could download the latest version of mochad by the original author mmauka, and update global.h and global.c with the two patch files in this directory. Here is a long bash command that will download the source and patches, and apply the latter.
wget -O mochad-0.1.17.tar.gz https://sourceforge.net/projects/mochad/files/mochad-0.1.17.tar.gz/download ; \
tar xzf mochad-0.1.17.tar.gz ; \
cd mochad-0.1.17 ; \
wget https://raw.githubusercontent.com/sigmdel/mochad/master/res/patch-global.c.diff ; \
patch global.c patch-global.c.diff ; \
wget https://raw.githubusercontent.com/sigmdel/mochad/master/res/patch-global.h.diff ; \
patch global.h patch-global.h.diff
Carry on with ./configure, make, sudo make install to complete the installation, but do not forget to install the prerequisite library, libusb-1.0-0-dev, before compiling the source code. Note that there is no need to install autoconf in Raspberry Pi OS because the configure script is used here instead of the autogen.sh script.