Address two truncation warnings in pcap_open_live().

These warnings have been around for a while in the REMOTE=yes space of
all Linux builds and OpenBSD/AMD64 build. Pass each of the offending
strings through a tailored buffer to satisfy GCC.

./pcap.c: In function 'pcap_open_live':
./pcap.c:2858:47: warning: '%.*s' directive output may be truncated
writing up to 250 bytes into a region of size between 249 and 252
[-Wformat-truncation=]
 2858 |   snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s (%.*s)", device,
      |                                               ^~~~
In file included from /usr/include/stdio.h:867,
                 from ./pcap.c:56:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:67:10: note:
'__builtin___snprintf_chk' output 6 or more bytes (assuming 259) into a
destination of size 256

./pcap.c:2853:43: warning: '%.*s' directive output may be truncated
writing up to 253 bytes into a region of size between 251 and 254
[-Wformat-truncation=]
 2853 |   snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %.*s", device,
      |                                           ^~~~
In file included from /usr/include/stdio.h:867,
                 from ./pcap.c:56:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:67:10: note:
'__builtin___snprintf_chk' output 3 or more bytes (assuming 259) into a
destination of size 256

0 files changed, 0 insertions, 0 deletions