mm: backing-dev: Remove duplicated macro definition

Move the K() macro a little forward to remove the same macro definition.

Link: https://lkml.kernel.org/r/d1ccdf2d3116dce9814f2bcc1f0415ecb4c76ea5.1612862230.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/backing-dev.c

@@ -32,6 +32,8 @@ LIST_HEAD(bdi_list);
 /* bdi_wq serves all asynchronous writeback tasks */
 struct workqueue_struct *bdi_wq;
 
+#define K(x) ((x) << (PAGE_SHIFT - 10))
+
 #ifdef CONFIG_DEBUG_FS
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
@@ -69,7 +71,6 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v)
 	global_dirty_limits(&background_thresh, &dirty_thresh);
 	wb_thresh = wb_calc_thresh(wb, dirty_thresh);
 
-#define K(x) ((x) << (PAGE_SHIFT - 10))
 	seq_printf(m,
 		   "BdiWriteback:       %10lu kB\n"
 		   "BdiReclaimable:     %10lu kB\n"
@@ -98,7 +99,6 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v)
 		   nr_more_io,
 		   nr_dirty_time,
 		   !list_empty(&bdi->bdi_list), bdi->wb.state);
-#undef K
 
 	return 0;
 }
@@ -146,8 +146,6 @@ static ssize_t read_ahead_kb_store(struct device *dev,
 	return count;
 }
 
-#define K(pages) ((pages) << (PAGE_SHIFT - 10))
-
 #define BDI_SHOW(name, expr)						\
 static ssize_t name##_show(struct device *dev,				\
 			   struct device_attribute *attr, char *buf)	\