Compile issue with the latest branch to add TRIM support

[fcrg]

System information

Type	Version/Name
Distribution Name	gentoo
Distribution Version
Linux Kernel	4.7.10
Architecture	x86_64
ZFS Version	PR 5925 ; dweeezil:ntrim2
SPL Version	spl-0.7.0-rc3

Describe the problem you're observing

Compile issue with the latest branch to add TRIM support

Describe how to reproduce the problem

compile with -Werror=implicit-function-declaration

Include any warning/errors/backtraces from the system logs

fs/zfs/zfs/metaslab.c: In function 'metaslab_auto_trim':
fs/zfs/zfs/metaslab.c:3835:6: error: implicit declaration of function 'trace_zfs_preserve__spilled' [-Werror=implicit-function-declaration]
DTRACE_PROBE1(preserve__spilled,
^
fs/zfs/zfs/metaslab.c:3842:6: error: implicit declaration of function 'trace_zfs_drop__spilled' [-Werror=implicit-function-declaration]
DTRACE_PROBE1(drop__spilled

fs/zfs/zfs/vdev.c: In function 'vdev_auto_trim':
fs/zfs/zfs/vdev.c:3830:2: error: implicit declaration of function 'trace_zfs_autotrim__mem__lim' [-Werror=implicit-function-declaration]
DTRACE_PROBE3(autotrim__mem__lim, vdev_t *, vd, uint64_t, mused,

[behlendorf]

This issue is related to the work going on in #5925 and should be reported there. @dweeezil I'm closing this issue and referencing #5925 so it can be resolved in that patch stack.