RFR (XXS): 8057143: Incomplete renaming of variables containing "hrs" to "hrm" related to HeapRegionSeq

[Thomas Schatzl]

Hi all,

  can I have reviews for the following tiny cleanup that fixes some
variable names?

In JDK-8054819 the HeapRegionSeq class has been renamed to
HeapRegionManager. During that, variables containing HeapRegionSeq
references were renamed, changing "hrs" to "hrm". 

There are some missing not renamed variables heapRegionRemSet.cpp.

CR:
https://bugs.openjdk.java.net/browse/JDK-8057143

Webrev:
http://cr.openjdk.java.net/~tschatzl/8057143/webrev/

Thanks,
  Thomas