doc: Fix typo in doucmentations

Correct typo (double words) in documentations.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index fc66d42..f4f268c 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -58,7 +58,7 @@
 		protocol entry point.
 
 Protocol 2.12:	(Kernel 3.8) Added the xloadflags field and extension fields
-	 	to struct boot_params for for loading bzImage and ramdisk
+	 	to struct boot_params for loading bzImage and ramdisk
 		above 4G in 64bit.
 
 **** MEMORY LAYOUT