RFR: 6205692: (spec) javax.crypto.MacSpi.engineUpdate(ByteBuffer input): NPE should be specified [v6]

[Kevin Driver]

> add @exception message to indicate an NPE might be thrown when the input parameter is null

Kevin Driver has updated the pull request incrementally with one additional commit since the last revision:

  remove unnecessary code

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/9859/files
  - new: https://git.openjdk.org/jdk/pull/9859/files/8fa4e15e..80c11e48

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9859&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9859&range=04-05

  Stats: 16 lines in 1 file changed: 0 ins; 13 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/9859.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9859/head:pull/9859

PR: https://git.openjdk.org/jdk/pull/9859