swiotlb: move struct io_tlb_slot to swiotlb.c

No need to expose this structure definition in the header.
Signed-off-by: Christoph Hellwig <hch@lst.de>

include/linux/swiotlb.h

@@ -101,11 +101,7 @@ struct io_tlb_mem {
 	unsigned int nareas;
 	unsigned int area_nslabs;
 	struct io_tlb_area *areas;
-	struct io_tlb_slot {
-		phys_addr_t orig_addr;
-		size_t alloc_size;
-		unsigned int list;
-	} *slots;
+	struct io_tlb_slot *slots;
 };
 extern struct io_tlb_mem io_tlb_default_mem;
 

kernel/dma/swiotlb.c

@@ -62,6 +62,12 @@
 
 #define INVALID_PHYS_ADDR (~(phys_addr_t)0)
 
+struct io_tlb_slot {
+	phys_addr_t orig_addr;
+	size_t alloc_size;
+	unsigned int list;
+};
+
 static bool swiotlb_force_bounce;
 static bool swiotlb_force_disable;