dma-buf: fix trivial typo error

Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

drivers/base/dma-buf.c

@@ -491,7 +491,7 @@ EXPORT_SYMBOL_GPL(dma_buf_kunmap);
  * 			dma-buf buffer.
  *
  * This function adjusts the passed in vma so that it points at the file of the
- * dma_buf operation. It alsog adjusts the starting pgoff and does bounds
+ * dma_buf operation. It also adjusts the starting pgoff and does bounds
  * checking on the size of the vma. Then it calls the exporters mmap function to
  * set up the mapping.
  *