Minor compiler warnings under Linux

[mcuee]

Here are some warnings under Linux (gcc 10.3, ARM64).

[ 74%] Building CXX object src/tools/CMakeFiles/hidpp10-load-temp-profile.dir/hidpp10-load-temp-profile.cpp.o
/home/mcuee/build/libusb/hidpp/src/tools/hidpp10-load-temp-profile.cpp: In function ‘int main(int, char**)’:
/home/mcuee/build/libusb/hidpp/src/tools/hidpp10-load-temp-profile.cpp:119:67: warning: narrowing conversion of ‘((profile_format.std::unique_ptr<HIDPP::AbstractProfileFormat>::operator->()->HIDPP::AbstractProfileFormat::size() + 1) / 2)’ from ‘size_t’ {aka ‘long unsigned int’} to ‘unsigned int’ [-Wnarrowing]
  119 |   HIDPP::Address macro_address { 0, 0, (profile_format->size ()+1)/2 };
      |                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
...

[ 98%] Building CXX object src/tools/CMakeFiles/hidpp20-led-control.dir/hidpp20-led-control.cpp.o
/home/mcuee/build/libusb/hidpp/src/tools/hidpp20-led-control.cpp: In function ‘int main(int, char**)’:
/home/mcuee/build/libusb/hidpp/src/tools/hidpp20-led-control.cpp:244:11: warning: unused variable ‘mode’ [-Wunused-variable]
  244 |      auto mode = Modes.value(argv[first_arg+1]);
      |           ^~~~

[mcuee]

There is a warning under MSYS2 mingw as well.

[79/99] Building CXX object src/tools/CMakeFiles/hidpp10-load-temp-profile.dir/hidpp10-load-temp-profile.cpp.obj
C:/work/libusb/hidpp/src/tools/hidpp10-load-temp-profile.cpp: In function 'int main(int, char**)':
C:/work/libusb/hidpp/src/tools/hidpp10-load-temp-profile.cpp:115:81: warning: narrowing conversion of '((profile_format.std::unique_ptr<HIDPP::AbstractProfileFormat>::operator->()->HIDPP::AbstractProfileFormat::size() + 1) / 2)' from 'size_t' {aka 'long long unsigned int'} to 'unsigned int' [-Wnarrowing]
  115 |                 HIDPP::Address macro_address { 0, 0, (profile_format->size ()+1)/2 };
      |                                                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
[99/99] Linking CXX executable src\tools\hidpp-persistent-profiles.exe

PS C:\work\libusb\hidpp> gcc -v
Using built-in specs.
COLLECT_GCC=C:\msys64\mingw64\bin\gcc.exe
COLLECT_LTO_WRAPPER=C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/lto-wrapper.exe
Target: x86_64-w64-mingw32
Configured with: ../gcc-12.2.0/configure --prefix=/mingw64 --with-local-prefix=/mingw64/local --build=x86_64-w64-mingw32 --host=x86_64-w64-mingw32 --target=x86_64-w64-mingw32 --with-native-system-header-dir=/mingw64/include --libexecdir=/mingw64/lib --enable-bootstrap --enable-checking=release --with-arch=nocona --with-tune=generic --enable-languages=c,lto,c++,fortran,ada,objc,obj-c++,jit --enable-shared --enable-static --enable-libatomic --enable-threads=posix --enable-graphite --enable-fully-dynamic-string --enable-libstdcxx-filesystem-ts --enable-libstdcxx-time --disable-libstdcxx-pch --enable-lto --enable-libgomp --disable-multilib --disable-rpath --disable-win32-registry --disable-nls --disable-werror --disable-symvers --with-libiconv --with-system-zlib --with-gmp=/mingw64 --with-mpfr=/mingw64 --with-mpc=/mingw64 --with-isl=/mingw64 --with-pkgversion='Rev10, Built by MSYS2 project' --with-bugurl=https://github.com/msys2/MINGW-packages/issues --with-gnu-as --with-gnu-ld --disable-libstdcxx-debug --with-boot-ldflags=-static-libstdc++ --with-stage1-ldflags=-static-libstdc++
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.2.0 (Rev10, Built by MSYS2 project)