RFR [XS]: 8239462: jdk.hotspot.agent misses some ReleaseStringUTFChars calls in case of early returns

[Baesken, Matthias]

Hello, please review this small change .
We miss at a few places ReleaseStringUTFChars  calls in the native
jdk.hotspot.agent  coding.
This happens in case of  early returns .


Bug/webrev :

https://bugs.openjdk.java.net/browse/JDK-8239462

http://cr.openjdk.java.net/~mbaesken/webrevs/8239462.0/


Thanks, Matthias