treewide: Fix typo in Documentation/DocBook

This patch fix spelling typo in Documentation/DocBook.
It is because .html and .xml files are generated by make htmldocs,
I have to fix a typo within the source files.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 75b9367..1274720 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1524,7 +1524,7 @@
  *	@dev: Device to which the command is sent
  *	@tf: Taskfile registers for the command and the result
  *	@cdb: CDB for packet command
- *	@dma_dir: Data tranfer direction of the command
+ *	@dma_dir: Data transfer direction of the command
  *	@sgl: sg list for the data buffer of the command
  *	@n_elem: Number of sg entries
  *	@timeout: Timeout in msecs (0 for default)
@@ -1712,7 +1712,7 @@
  *	@dev: Device to which the command is sent
  *	@tf: Taskfile registers for the command and the result
  *	@cdb: CDB for packet command
- *	@dma_dir: Data tranfer direction of the command
+ *	@dma_dir: Data transfer direction of the command
  *	@buf: Data buffer of the command
  *	@buflen: Length of data buffer
  *	@timeout: Timeout in msecs (0 for default)