aio_read.2: correct the description of aio_buf

Looks like a copypasta from aio_write.2.

[skip ci]

Reported by:	Paul Floyd <pjfloyd@wanadoo.fr>
MFC after:	1 week
Sponsored by:	Axcient
Reviewed by:	jilles (manpages)
Differential Revision: https://reviews.freebsd.org/D42621

lib/libc/sys/aio_read.2

@@ -22,7 +22,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd January 2, 2021
+.Dd November 15, 2023
 .Dt AIO_READ 2
 .Os
 .Sh NAME
@@ -51,7 +51,7 @@ beginning at the offset
 .Fn aio_read
 will read
 .Fa iocb->aio_nbytes
-from the buffer pointed to by
+into the buffer pointed to by
 .Fa iocb->aio_buf ,
 whereas
 .Fn aio_readv