crypto: lib/blake2s - Move selftest prototype into header file

This patch fixes a missing prototype warning on blake2s_selftest.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/crypto/internal/blake2s.h

@@ -16,6 +16,8 @@ void blake2s_compress_generic(struct blake2s_state *state,const u8 *block,
 void blake2s_compress_arch(struct blake2s_state *state,const u8 *block,
 			   size_t nblocks, const u32 inc);
 
+bool blake2s_selftest(void);
+
 static inline void blake2s_set_lastblock(struct blake2s_state *state)
 {
 	state->f[0] = -1;

lib/crypto/blake2s-selftest.c

@@ -3,7 +3,7 @@
  * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
  */
 
-#include <crypto/blake2s.h>
+#include <crypto/internal/blake2s.h>
 #include <linux/string.h>
 
 /*

lib/crypto/blake2s.c

@@ -17,8 +17,6 @@
 #include <linux/bug.h>
 #include <asm/unaligned.h>
 
-bool blake2s_selftest(void);
-
 void blake2s_update(struct blake2s_state *state, const u8 *in, size_t inlen)
 {
 	const size_t fill = BLAKE2S_BLOCK_SIZE - state->buflen;