Allow building ZFS with Clang

[extSunset]

I suggest removing workaround to allow building ZFS with Clang (LTO), but with -Wno-error=uninitialized added to KCFLAGS when building ZFS.

linux-cachyos/linux-cachyos/PKGBUILD

Lines 304 to 308 in 7bf97b1

	### Prevent ZFS and LTO building at the same time
	# More infos here: https://github.com/openzfs/zfs/issues/15384
	if [[ "$_use_llvm_lto" != "none" && -n "$_build_zfs" ]]; then
	_die "ZFS and LTO support cannot be built at the same time. "
	fi

Or a patch could be added based on this comment.
openzfs/zfs#15384 (comment)

[ptr1337]

Hi,

I will try the next days adding -Wno-error=uninitialized.
You could also try adding the folliowing before the ZFS part:

export KCPPFLAGS+=' -Wno-error=uninitialized
export KCFLAGS+=' -Wno-error=uninitialized

Edit:
Personally I think, zfs should really care about to bring a patch for this. Also they should add a CI for Clang as default.

[ptr1337]

Fix does work. We will add it to the PKBUILD as a temporally workaround.