RFR (XXS): 8154838: G1CardLiveData::free_large_bitmap() uses wrong calculation to determine the number of words

[Thomas Schatzl]

Hi all,

  could I have reviews for this one-line change that fixes calculation
of the number of words for a given size in bits in
 G1CardLiveData::free_large_bitmap()?

The change is to use the exact same calculation as in
 G1CardLiveData::allocate_large_bitmap() for uniformity.

There is no semantic difference in both since the size_in_bits
parameter is always word-aligned anyway.

CR:
https://bugs.openjdk.java.net/browse/JDK-8154838
Webrev:
http://cr.openjdk.java.net/~tschatzl/8154838/webrev/
Testing:
local compilation, local run of gcbasher

Thanks,
  Thomas