BList: Slight code and parameter name cleanup.

* Clarify the fResizeThreshold logic and remove the comment.

 * Rename "count" constructor argument to "blockSize", as this is
   what it actually does.

No functional change intended.

Change-Id: I993bf0e695f47da181e9fb50b9a964edfd4a0adc
Reviewed-on: https://review.haiku-os.org/c/haiku/+/8629
Reviewed-by: waddlesplash <[email protected]>

headers/os/support/List.h

@@ -11,7 +11,7 @@
 
 class BList {
 public:
-								BList(int32 count = 20);
+								BList(int32 blockSize = 20);
 								BList(const BList& other);
 	virtual						~BList();
 

src/kits/support/List.cpp

@@ -29,12 +29,12 @@ move_items(void** items, int32 offset, int32 count)
 }
 
 
-BList::BList(int32 count)
+BList::BList(int32 blockSize)
 	:
 	fObjectList(NULL),
 	fPhysicalSize(0),
 	fItemCount(0),
-	fBlockSize(count),
+	fBlockSize(blockSize),
 	fResizeThreshold(0)
 {
 	if (fBlockSize <= 0)
@@ -474,7 +474,6 @@ void BList::_ReservedList2() {}
 bool
 BList::_ResizeArray(int32 count)
 {
-	bool result = true;
 	// calculate the new physical size
 	// by doubling the existing size
 	// until we can hold at least count items
@@ -490,16 +489,17 @@ BList::_ResizeArray(int32 count)
 		newSize = fResizeThreshold;
 
 	// resize if necessary
+	bool result = true;
 	if (newSize != fPhysicalSize) {
 		void** newObjectList
 			= (void**)realloc(fObjectList, newSize * sizeof(void*));
 		if (newObjectList) {
 			fObjectList = newObjectList;
 			fPhysicalSize = newSize;
-			// set our lower bound to either 1/4
-			//of the current physical size, or 0
-			fResizeThreshold = fPhysicalSize >> 2 >= fBlockSize
-				? fPhysicalSize >> 2 : 0;
+
+			fResizeThreshold = (fPhysicalSize / 4);
+			if (fResizeThreshold < fBlockSize)
+				fResizeThreshold = 0;
 		} else
 			result = false;
 	}