sprintf/strcpy in qzip.c

[wdoekes]

cc -g -O2 -fdebug-prefix-map=/build/qpress-1.1=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -DQLZ_MEMORY_SAFE -DQLZ_COMPRESSION_LEVEL=1 -DQLZ_STREAMING_BUFFER=1048576 -o qlzip1 qzip.c quicklz.c -Wl,-z,relro
qzip.c: In function 'main':
qzip.c:274:29: warning: '%d' directive output may be truncated writing between 1 and 11 bytes into a region of size between 0 and 1023 [-Wformat-truncation=]
                         "%s.%d", fn_buffer, getpid());
                             ^~
In file included from /usr/include/stdio.h:873,
                 from qzip.c:8:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:67:10: note: '__builtin___snprintf_chk' output between 3 and 1036 bytes into a destination of size 1024
   return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        __bos (__s), __fmt, __va_arg_pack ());
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~