qemu-io: Fix spelling in help message.

excerciser -> exerciser

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/qemu-io.c b/qemu-io.c
index e2a3a1b..327dd30 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -1033,7 +1033,7 @@
 {
 	printf(
 "Usage: %s [-h] [-V] [-Crsnm] [-c cmd] ... [file]\n"
-"QEMU Disk excerciser\n"
+"QEMU Disk exerciser\n"
 "\n"
 "  -C, --create         create new file if it doesn't exist\n"
 "  -c, --cmd            command to execute\n"