RFR: 8254995: [x86] ControlWord::print(), rc/pc variables might not be initialized

[Aleksey Shipilev]

Static analyzers complain that in `ControlWord::print()`, `rc`/`pc` variables might not be initialized. This never
happens in practice, because `rounding_control()` and `precision_control()` return the good values. We can make it
cleaner to silence the compiler.

Testing:
  - [x] Linux x86_64 tier1

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

Commit messages:
 - 8254995: [x86] ControlWord::print(), rc/pc variables might not be initialized

Changes: https://git.openjdk.java.net/jdk/pull/731/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=731&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8254995
  Stats: 6 lines in 1 file changed: 6 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/731.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/731/head:pull/731

PR: https://git.openjdk.java.net/jdk/pull/731