RFR: 8257858: [macOS]: Remove JNF dependency from libosxsecurity/KeystoreImpl.m [v7]

[Weijun Wang]

> This fix covers both
> 
> - [[macOS]: Remove JNF dependency from libosxsecurity/KeystoreImpl.m](https://bugs.openjdk.java.net/browse/JDK-8257858)
> - [[macOS]: Remove JNF dependency from libosxkrb5/SCDynamicStoreConfig.m](https://bugs.openjdk.java.net/browse/JDK-8257860)

Weijun Wang has updated the pull request incrementally with two additional commits since the last revision:

 - file attr error
 - objc use .m

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1845/files
  - new: https://git.openjdk.java.net/jdk/pull/1845/files/ef337f12..b5f1e15d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1845&range=06
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1845&range=05-06

  Stats: 6 lines in 4 files changed: 0 ins; 1 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1845.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1845/head:pull/1845

PR: https://git.openjdk.java.net/jdk/pull/1845