Change order of kernel include directories to work around build failure under
MacOSX 10.6.4 with XCode 3.2.4 installed.
Problem is, that with XCode install, the old order picked up the Private Kernel Headers
first, which resulted in a redefinition error for lbolt.  Using the normal
Kernel Headers first solves the problem.

*** This changes Makefile.am ***
*** you must re-run autogen.sh ***