some functions in the tcp module can be static

*** 46,56 ****
   * TCP_STAT(name) does non-atomic increment of a named stat counter. It is
   * supposed to be used in non MT-hot paths of the code.
   *
   * TCP_DBGSTAT(name) does atomic increment of a named stat counter. It is
   * supposed to be used for DEBUG purposes and may be used on a hot path.
!  * These counters are only available in a debugged kerel.  They are grouped
   * under the TCP_DEBUG_COUNTER C pre-processor condition.
   *
   * Both TCP_STAT and TCP_DBGSTAT counters are available using kstat
   * (use "kstat tcp" to get them).
   *
--- 46,56 ----
   * TCP_STAT(name) does non-atomic increment of a named stat counter. It is
   * supposed to be used in non MT-hot paths of the code.
   *
   * TCP_DBGSTAT(name) does atomic increment of a named stat counter. It is
   * supposed to be used for DEBUG purposes and may be used on a hot path.
!  * These counters are only available in a debugged kernel.  They are grouped
   * under the TCP_DEBUG_COUNTER C pre-processor condition.
   *
   * Both TCP_STAT and TCP_DBGSTAT counters are available using kstat
   * (use "kstat tcp" to get them).
   *