sparc/iommu: fix typo s/265KB/256KB/

IOMMU_NPTES is 64K PTEs, so the size is 256KB (= 64K * sizeof(iopte_t))
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/mm/iommu.c

@@ -34,7 +34,7 @@
 #define IOMMU_RNGE	IOMMU_RNGE_256MB
 #define IOMMU_START	0xF0000000
 #define IOMMU_WINSIZE	(256*1024*1024U)
-#define IOMMU_NPTES	(IOMMU_WINSIZE/PAGE_SIZE)	/* 64K PTEs, 265KB */
+#define IOMMU_NPTES	(IOMMU_WINSIZE/PAGE_SIZE)	/* 64K PTEs, 256KB */
 #define IOMMU_ORDER	6				/* 4096 * (1<<6) */
 
 /* srmmu.c */