qemu-io: end aio help text sentences with periods

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
diff --git a/qemu-io.c b/qemu-io.c
index ffa62fb..938b20c 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -1118,7 +1118,7 @@
 " Reads a segment of the currently open file, optionally dumping it to the\n"
 " standard output stream (with -v option) for subsequent inspection.\n"
 " The read is performed asynchronously and the aio_flush command must be\n"
-" used to ensure all outstanding aio requests have been completed\n"
+" used to ensure all outstanding aio requests have been completed.\n"
 " -C, -- report statistics in a machine parsable format\n"
 " -P, -- use a pattern to verify read data\n"
 " -v, -- dump buffer to standard output\n"
@@ -1214,7 +1214,7 @@
 " Writes into a segment of the currently open file, using a buffer\n"
 " filled with a set pattern (0xcdcdcdcd).\n"
 " The write is performed asynchronously and the aio_flush command must be\n"
-" used to ensure all outstanding aio requests have been completed\n"
+" used to ensure all outstanding aio requests have been completed.\n"
 " -P, -- use different pattern to fill file\n"
 " -C, -- report statistics in a machine parsable format\n"
 " -q, -- quiet mode, do not show I/O statistics\n"