arch/powerpc/platforms/pseries/hotplug-memory.c: fix section handling code

Fix

  arch/powerpc/platforms/pseries/hotplug-memory.c: In function 'pseries_remove_memblock':
  arch/powerpc/platforms/pseries/hotplug-memory.c:103:17: error: unused variable 'pfn' [-Werror=unused-variable]

Caused by commit d760afd4 ("memory-hotplug: suppress "Trying to free
nonexistent resource <XXXXXXXXXXXXXXXX-YYYYYYYYYYYYYYYY>" warning").
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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

@@ -101,7 +101,7 @@ static int pseries_remove_memblock(unsigned long base, unsigned int memblock_siz
 	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;
-		ret = __remove_pages(zone, start_pfn,  PAGES_PER_SECTION);
+		ret = __remove_pages(zone, pfn, PAGES_PER_SECTION);
 		if (ret)
 			return ret;
 	}