lguest: Fix three simple typos in comments

This patch fixes three typos I've accidentally spotted.

Signed-off-by: Adrian Knoth <adi@drcomp.erfurt.thur.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (one was already fixed)
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index 7427990..5c4f240 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -467,7 +467,7 @@
 	/*
 	 * PAE systems can mark pages as non-executable.  Linux calls this the
 	 * NX bit.  Intel calls it XD (eXecute Disable), AMD EVP (Enhanced
-	 * Virus Protection).  We just switch turn if off here, since we don't
+	 * Virus Protection).  We just switch it off here, since we don't
 	 * support it.
 	 */
 	case 0x80000001: