Revert "lzma: Make sure we don't dereference past array"

Revert "lzma: Make sure we don't dereference past array"

Commit 40e261b89b71 (lib/LzmaEnc: Validate "len" before subtracting)
ensures that the variable len is at least 2. As a result, GetLenToPosState(len)
never returns a value greater than or equal to kNumLenToPosStates,
making the changes introduced in the commit 16c0dbf4bc6a (lzma: Make
sure we don't dereference past array) unreachable and no longer necessary.

This reverts commit 16c0dbf4bc6a (lzma: Make sure we don't dereference past array).

Fixes: CID 481982
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>