make clean fails

[duncan-bayne]

On FreeBSD 11.2 amd64 (with #14 merged), make clean fails:

gmake[1]: Entering directory '/usr/home/duncan/code/blink1-tool'
rm -f ./hidapi/libusb/hid.o blink1-lib.o
rm -f libblink1.so
rm -f blink1-tiny-server.o blink1-tool.o hiddata.o
rm -f server/mongoose/mongoose.o
rm -f blink1-tool blink1-tiny-server
make -C blink1control-tool clean
make[2]: don't know how to make w. Stop

make[2]: stopped in /usr/home/duncan/code/blink1-tool/blink1control-tool
gmake[1]: *** [GNUmakefile:567: clean] Error 2
gmake[1]: Leaving directory '/usr/home/duncan/code/blink1-tool'
*** Error code 2

Stop.
make: stopped in /usr/home/duncan/code/blink1-tool

[todbot]

Think I fixed this. Thanks!