compilation: Fix compilation errors

Fix some compilation errors that would arrise when NDEBUG is defined:
 - tests/misc-tcp.cc: missing #include<iostream> that would come from
   include/boost/assert.hpp: line 81 when NDEBUG is not defined.
 - bsd/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c:
   when NDEBUG is not defined assert() is defined to __assert_fail,
   which has "noreturn" attribute, which satisfies the compiler.
   When NDEBUG is defined and assert() completly compiles out, the
   compiler start complaining about the missing "return" statment.

Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>