m68k: Fix misspellings in comments.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Acked-by: Greg Ungerer <gerg@uclinux.org> [nommu, coldfire]
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
diff --git a/arch/m68k/include/asm/mac_iop.h b/arch/m68k/include/asm/mac_iop.h
index fde874a..42566fd 100644
--- a/arch/m68k/include/asm/mac_iop.h
+++ b/arch/m68k/include/asm/mac_iop.h
@@ -48,7 +48,7 @@
 
 /* IOP message status codes */
 
-#define IOP_MSGSTATUS_UNUSED	0	/* Unusued message structure       */
+#define IOP_MSGSTATUS_UNUSED	0	/* Unused message structure        */
 #define IOP_MSGSTATUS_WAITING	1	/* waiting for channel             */
 #define IOP_MSGSTATUS_SENT	2	/* message sent, awaiting reply    */
 #define IOP_MSGSTATUS_COMPLETE	3	/* message complete and reply rcvd */