trap from DEBUG_LOCKS

[Kris Kennaway]

The insta-panic at boot on sparc64 with RELENG_7 seems to be fixed, but 
at the point when it mounts root I get the following panic when 
DEBUG_LOCKS is enabled:

panic: trap: memory address not aligned
cpuid = 9
KDB: enter: panic
[thread pid 1 tid 100006 ]
Stopped at      kdb_enter+0x68: ta              %xcc, 1
db> wh
Tracing pid 1 tid 100006 td 0xfffff800020709c0
panic() at panic+0x204
trap() at trap+0x56c
-- memory address not aligned sfar=0xe2f47c27 sfsr=0x40029 %o7=0xc03cd524 --
stack_save() at stack_save+0x18
_lockmgr() at _lockmgr+0x4c
vfs_busy() at vfs_busy+0x1d4
vfs_mount_alloc() at vfs_mount_alloc+0x58
vfs_mountroot() at vfs_mountroot+0x2e4
start_init() at start_init+0x58
fork_exit() at fork_exit+0x9c
fork_trampoline() at fork_trampoline+0x8

Kris