Use sysctl_handle_long() instead of duplicating it's logic for kern.ipc.maxsockbuf so that this sysctl works for 32-bit binaries running on amd64 via compat/freebsd32.
Use sysctl_handle_long() instead of duplicating it's logic for
kern.ipc.maxsockbuf so that this sysctl works for 32-bit binaries running
on amd64 via compat/freebsd32.

MFC after:	3 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase