mm: Remove unused variable idx0 in __early_ioremap()

After commit:

   8827247f ("x86: don't define __this_fixmap_does_not_exist()")

variable idx0 is no longer needed, so just remove it.
Signed-off-by: NJianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <linux-mm@kvack.org>
Cc: <wangchen@cn.fujitsu.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Link: http://lkml.kernel.org/r/5209A173.3090600@huawei.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

arch/x86/mm/ioremap.c

@@ -487,7 +487,7 @@ __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
 	unsigned long offset;
 	resource_size_t last_addr;
 	unsigned int nrpages;
-	enum fixed_addresses idx0, idx;
+	enum fixed_addresses idx;
 	int i, slot;
 
 	WARN_ON(system_state != SYSTEM_BOOTING);
@@ -540,8 +540,7 @@ __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
 	/*
 	 * Ok, go for it..
 	 */
-	idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
-	idx = idx0;
+	idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
 	while (nrpages > 0) {
 		early_set_fixmap(idx, phys_addr, prot);
 		phys_addr += PAGE_SIZE;