Simplify 32-bit long offsets decoding logic

Simplify 32-bit long offsets decoding logic

The previous code had an issue when `bitsConsumed == 32` it would read 0
bits for the `ofBits` read, which violates the precondition of
`BIT_readBitsFast()`. This can happen when the stream is corrupted.

Fix thie issue by always reading the maximum possible number of extra
bits. I've measured neutral decoding performance, likely because this
branch is unlikely, but this should be faster anyways. And if not, it is
only 32-bit decoding, so performance isn't as critical.

Credit to OSS-Fuzz