bug #2442: Fix bmake regression of kernel build
Kernel modules such as acpi.ko didn't load due to missing symbols after
bmake replaced legacy make. The cause was traced back to a badly
generated header which in turn was caused by the file kern.fwd.mk. That
file contained ":U" modifiers that should have been converted to ":tu"
modifiers.
The actual cause of the missing symbols were due to atomic.h not getting
included into atomic.c twice. Case sensitivity prevented a macro from
being properly unset. The modifiers in question turn everything to
upper case.
A full kernel build is required to fix the module loading.