kernel: The COMPAT_DF12 kernel option is pc32 specific.
kernel: The NPX_DEBUG kernel option is pc32 specific, too.
kprintf(9): Implement optional 'precision' for numbers.

Previously, it was parsed but ignored. Some third-party modules
(e.g., APCICA) prefer this format over zero padding flag '0'.

Before this commit:

ACPI Warning: 32/64X FACS address mismatch in FADT - 0x3F611E40/0x       03F611D40, using 32 (20110527/tbfadt-589)

After this commit:

ACPI Warning: 32/64X FACS address mismatch in FADT - 0x3F611E40/0x000000003F611D40, using 32 (20110527/tbfadt-589)

Taken-from: FreeBSD (r209836 and r209949)
kernel: Remove some unused variables in network drivers.