SVN r377448 breaks net-snmp on -current

Apparently, there was some 'magic' to accessing these sysctls:

libtool: link: cc -DNETSNMP_ENABLE_IPV6 -fno-strict-aliasing -O2 -pipe
-march=pentium4 -I/usr/local/include -I/include -D_WANT_IFADDR
-fstack-protector -fno-strict-aliasing -Ufreebsd11 -Dfreebsd11=freebsd11
-DHAS_FPSETMASK -DHAS_FLOATINGPOINT_H -fno-strict-aliasing -pipe
-fstack-protector -I/usr/local/include
-I/usr/local/lib/perl5/5.18/mach/CORE -o .libs/snmpd .libs/snmpd.o
-Wl,-R/usr/local/lib/perl5/5.18/mach/CORE  -L/usr/lib -L/lib
./.libs/libnetsnmpagent.so -L/usr/local/lib
-L/usr/local/lib/perl5/5.18/mach/CORE ./.libs/libnetsnmpmibs.so
/usr/ports/net-mgmt/net-snmp/work/net-snmp-5.7.3/agent/.libs/libnetsnmpagent.so
/usr/ports/net-mgmt/net-snmp/work/net-snmp-5.7.3/snmplib/.libs/libnetsnmp.so
../snmplib/.libs/libnetsnmp.so -lpkg -lwrap -lperl -lcrypt -lutil -lelf
-lssp_nonshared -lm -lkvm -ldevstat -lcrypto -pthread  -Wl,-rpath
-Wl,/usr/local/lib
./.libs/libnetsnmpmibs.so: undefined reference to `sysctl_read_icmp_stat'
./.libs/libnetsnmpmibs.so: undefined reference to `sysctl_read_icmp6_stat'
./.libs/libnetsnmpmibs.so: undefined reference to
`sysctl_read_icmp6_msg_stat'
./.libs/libnetsnmpmibs.so: undefined reference to
`sysctl_read_icmp_msg_stat'
cc: error: linker command failed with exit code 1 (use -v to see invocation)
*** Error code 1

	imb