fs/direct-io: remove redundant assignment to variable retval

The variable retval is being assigned a value that is not being read,
it is being re-assigned later on in the function. The assignment
is redundant and can be removed.

Cleans up clang scan build warning:
fs/direct-io.c:1220:2: warning: Value stored to 'retval' is never
read [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20240410162221.292485-1-colin.i.king@gmail.comReviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs/direct-io.c

@@ -1217,7 +1217,6 @@ ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
 	 */
 	inode_dio_begin(inode);
 
-	retval = 0;
 	sdio.blkbits = blkbits;
 	sdio.blkfactor = i_blkbits - blkbits;
 	sdio.block_in_file = offset >> blkbits;