lib/halfmd4.c: simplify includes

We only need EXPORT_SYMBOL, so compiler.h and export.h suffice.  This
means linux/types.h is no longer implicitly included, so add an include of
uapi/linux/types.h to linux/cryptohash.h for __u32.  Other users of
cryptohash.h cannot be affected, since they must already have been
including uapi/linux/types.h in order for gcc not to complain about
unknown types.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/cryptohash.h

 #ifndef __CRYPTOHASH_H
 #define __CRYPTOHASH_H
 
+#include <uapi/linux/types.h>
+
 #define SHA_DIGEST_WORDS 5
 #define SHA_MESSAGE_BYTES (512 /*bits*/ / 8)
 #define SHA_WORKSPACE_WORDS 16

lib/halfmd4.c

-#include <linux/kernel.h>
+#include <linux/compiler.h>
 #include <linux/export.h>
 #include <linux/cryptohash.h>