[compression] Use new lz4 API
[compression] Use new lz4 API

In the new version (v1.9.1) of lz4, `LZ4_decompress_fast()` is deprecated
and unsafe. It is recommended to use `LZ4_decompress_safe()`

The documentation in lz4.h is as follows:

/*! LZ4_decompress_fast() : **unsafe!**
 *  These functions used to be faster than LZ4_decompress_safe(),
 *  but it has changed, and they are now slower than LZ4_decompress_safe().
 *  This is because LZ4_decompress_fast() doesn't know the input size,
 *  and therefore must progress more cautiously in the input buffer to not read beyond the end of
    block.
 *  On top of that `LZ4_decompress_fast()` is not protected vs malformed or malicious inputs,
    making it a security liability.
 *  As a consequence, LZ4_decompress_fast() is strongly discouraged, and deprecated.
 */

Change-Id: Ib343fda7fff1d14ee7bc551be3ac87b068504359
Reviewed-on: http://gerrit.cloudera.org:8080/14587
Tested-by: Kudu Jenkins
Reviewed-by: Adar Dembo <866ca730bfc7f544e3ebce604ceeba4879f23df0@cloudera.com>

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