arch/powerpc/platforms/pseries/hotplug-memory.c: section removal cleanups

Followups to d760afd4d257 ("memory-hotplug: suppress "Trying to free
nonexistent resource <XXXXXXXXXXXXXXXX-YYYYYYYYYYYYYYYY>" warning").

 - use unsigned long type, as overflows are conceivable

 - rename `i' to the less-misleading and more informative `section'

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/platforms/pseries/hotplug-memory.c

@@ -77,8 +77,9 @@ static int pseries_remove_memblock(unsigned long base, unsigned int memblock_siz
 {
 	unsigned long start, start_pfn;
 	struct zone *zone;
-	int i, ret;
-	int sections_to_remove;
+	int ret;
+	unsigned long section;
+	unsigned long sections_to_remove;
 
 	start_pfn = base >> PAGE_SHIFT;
 
@@ -99,8 +100,8 @@ static int pseries_remove_memblock(unsigned long base, unsigned int memblock_siz
 	 * while writing to it. So we have to defer it to here.
 	 */
 	sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION;
-	for (i = 0; i < sections_to_remove; i++) {
-		unsigned long pfn = start_pfn + i * PAGES_PER_SECTION;
+	for (section = 0; section < sections_to_remove; section++) {
+		unsigned long pfn = start_pfn + section * PAGES_PER_SECTION;
 		ret = __remove_pages(zone, pfn, PAGES_PER_SECTION);
 		if (ret)
 			return ret;