(split) Use m_getcl() instead of MGETHDR/MCLGET macros.

Suggested by:	glebius
(split) Use m_get2() instead of m_getcl().

Spotted by:	glebius
(split) Fix a logic error when checking if Tx power entries are greater than 31.
(split) Merge branch 'CURRENT' (commit '6265cc52')