This patch fixes two problems:

1. Frees memory malloced by the kernel that was 
   previously not freed.  The malloc was very often 
   used by vfast operations.

2. Avoids two types of panics resulting from 
   quotactl requests on advfs filesets:
      - kmf in dyn_hash_remove
      - panic "lock_terminate: lock held"

Partial stack traces for the two quotactl panicing threads follow.

1) panic "lock_terminate: lock held"

    4 panic() "lock_terminate: lock held")
    5 lock_terminate()
    6 dqput()
    7 advfs_get_quota() 
    8 advfs_quotactl() 
    9 cfs_comm_quotactl()
   10 cfs_quotactl()
   11 quotactl()
   12 syscall()
   13 _Xsyscall()

2) kernel memory fault in dyn_hash_remove:

    4 panic
    5 trap 
    6 _XentMM()
    7 dyn_hash_remove()
    8 dqput()
    9 advfs_get_quota()
   10 advfs_quotactl()
   11 cfs_comm_quotactl()
   12 cfs_quotactl()
   13 quotactl()
   14 syscall()
   15 _Xsyscall()


