[Documentation] Fix log parameter error and spelling error

In ConstantSizeRegionSplitPolicy.isExceedSize(),

'''

if (size > sizeToCheck) {
LOG.debug("ShouldSplit because {} size={}, sizeToCheck={}{}",
store.getColumnFamilyName(), StringUtils.humanSize(size),
StringUtils.humanSize(sizeToCheck));
return true;
}

'''

There should be only three parameters, remove last '{}'