OpenBSD gcc issues warnings for some suspicious constructs, like:
slirp/tcp_subr.c:1077: warning: Array size (256) smaller than format
string size (257) (arg 3)
vl.o(.text+0x7bc0): In function `drive_init':
vl.c:5464: warning: strcpy() is almost always misused, please use strlcpy()

This patch silences the warnings. Comments?