mtd: ftl: use swap() in copy_erase_unit()

Use kernel.h macro definition.

Thanks to Julia Lawall for Coccinelle scripting support.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/ftl.c

@@ -571,12 +571,8 @@ static int copy_erase_unit(partition_t *part, uint16_t srcunit,
 
 
     /* Update the maps and usage stats*/
-    i = xfer->EraseCount;
-    xfer->EraseCount = eun->EraseCount;
-    eun->EraseCount = i;
-    i = xfer->Offset;
-    xfer->Offset = eun->Offset;
-    eun->Offset = i;
+    swap(xfer->EraseCount, eun->EraseCount);
+    swap(xfer->Offset, eun->Offset);
     part->FreeTotal -= eun->Free;
     part->FreeTotal += free;
     eun->Free = free;