btrfs-progs: crypto: declare SHA256 x86 optimized implementation

The optimized implementation sha256_process_x86() is not declared
anywhere, this can be caught by -Wmissing-prototypes option.

Just declare it properly in sha.h.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

crypto/sha.h

@@ -211,4 +211,7 @@ extern int hmacResult(HMACContext *context,
 
 void sha256_init_accel(void);
 
+/* Export for optimized version to silent -Wmissing-prototypes. */
+void sha256_process_x86(uint32_t state[8], const uint8_t data[], uint32_t length);
+
 #endif /* _SHA_H_ */

crypto/sha256-x86.c

@@ -13,6 +13,8 @@
 # include <x86intrin.h>
 #endif
 
+#include "sha.h"
+
 /* Process multiple blocks. The caller is responsible for setting the initial */
 /*  state, and the caller is responsible for padding the final block.        */
 void sha256_process_x86(uint32_t state[8], const uint8_t data[], uint32_t length)