dma-buf: Fix kerneldoc formatting

I wanted to look up something and noticed the hyperlink doesn't work.
While fixing that also noticed a trivial kerneldoc comment typo in the
same section, fix that too.
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Reviewed-by: Simon Ser <contact@emersion.fr>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201204200242.2671481-1-daniel.vetter@ffwll.ch

Documentation/driver-api/dma-buf.rst

@@ -190,7 +190,7 @@ DMA Fence uABI/Sync File
 Indefinite DMA Fences
 ~~~~~~~~~~~~~~~~~~~~~
 
-At various times &dma_fence with an indefinite time until dma_fence_wait()
+At various times struct dma_fence with an indefinite time until dma_fence_wait()
 finishes have been proposed. Examples include:
 
 * Future fences, used in HWC1 to signal when a buffer isn't used by the display

include/linux/dma-buf-map.h

@@ -122,7 +122,7 @@ struct dma_buf_map {
 
 /**
  * DMA_BUF_MAP_INIT_VADDR - Initializes struct dma_buf_map to an address in system memory
- * @vaddr:	A system-memory address
+ * @vaddr_:	A system-memory address
  */
 #define DMA_BUF_MAP_INIT_VADDR(vaddr_) \
 	{ \