xlunzip fails to build with GCC-10

[Daniel Baumann]

Hi Antonio

Debian is switching at some point to GCC-10, xlunzip fails to build with
the following error:

[...]
x86_64-linux-gnu-gcc-10 -g  -Wall -W -O2 -c -o carg_parser.o carg_parser.c
x86_64-linux-gnu-gcc-10 -g  -Wall -W -O2 -c -o decompress_lunzip.o
decompress_lunzip.c
x86_64-linux-gnu-gcc-10 -g  -Wall -W -O2 -c -o in_place.o in_place.c
x86_64-linux-gnu-gcc-10 -g  -Wall -W -O2 -c -o lzip_decompress.o
lzip_decompress.c
x86_64-linux-gnu-gcc-10 -g  -Wall -W -O2 -DPROGVERSION=\"0.4\" -c -o
main.o main.c
x86_64-linux-gnu-gcc-10 -g  -Wall -W -O2 -o xlunzip carg_parser.o
decompress_lunzip.o in_place.o lzip_decompress.o main.o
/usr/bin/ld: main.o:/build/xlunzip/main.c:438: multiple definition of
`global_name'; in_place.o:/build/xlunzip/in_place.c:149: first defined here
collect2: error: ld returned 1 exit status
make[1]: *** [Makefile:44: xlunzip] Error 1
make[1]: Leaving directory '/build/xlunzip'

Regards,
Daniel