spelling: s/appropiate/appropriate/

Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/Documentation/ioctl/hdio.txt b/Documentation/ioctl/hdio.txt
index 9a7aea0..11c9be4 100644
--- a/Documentation/ioctl/hdio.txt
+++ b/Documentation/ioctl/hdio.txt
@@ -946,7 +946,7 @@
 
 	  This ioctl initializes the addresses and irq for a disk
 	  controller, probes for drives, and creates /proc/ide
-	  interfaces as appropiate.
+	  interfaces as appropriate.