Fix accel-cmd compile problem on Raspbian Buster

With GCC v8.x on Raspbian Buster the following warning is shown
at compile time:

...
[ 99%] Building C object accel-cmd/CMakeFiles/accel-cmd.dir/accel_cmd.c.o
/home/pi/accel-ppp/accel-cmd/accel_cmd.c: In function ‘main’:
/home/pi/accel-ppp/accel-cmd/accel_cmd.c:652:29: warning: comparison is always true due to limited range of data type [-Wtype-limits]
         long_opts, &oindx)) != -1) {
                             ^~
[100%] Linking C executable accel-cmd
[100%] Built target accel-cmd

This leads to the accel-cmd always just showing the usage
instructions rather than executing any commands.

This is because ochar is declared as a char rather than an int
so is considered to be unsigned by default. The man page says
the return value should be an int.

https://linux.die.net/man/3/getopt_long

0 files changed, 0 insertions, 0 deletions