[MTD] Remove #ifndef __KERNEL__ hack in <mtd/mtd-abi.h>

Now that we have headers_install, we don't need this crap.

Signed-off-by: David Woodhouse <[e-mail]>

include/mtd/Kbuild

···
-unifdef-y := mtd-abi.h
-header-y := inftl-user.h jffs2-user.h mtd-user.h nftl-user.h
+header-y := inftl-user.h jffs2-user.h mtd-abi.h mtd-user.h nftl-user.h

include/mtd/mtd-abi.h

···
 #ifndef __MTD_ABI_H__
 #define __MTD_ABI_H__
 
-#ifndef __KERNEL__ 
-/* Urgh. The whole point of splitting this out into
-   separate files was to avoid #ifdef __KERNEL__ */
-#define __user
-#endif
-
 struct erase_info_user {
 	uint32_t start;
 	uint32_t length;