ed25519: Harmonize arguments to make new gcc happy

This started failing CI on Fedora with new GCC

/builds/jjelen/libssh-mirror/src/external/ed25519.c:80:48: error: argument 1 of type 'unsigned char *' declared as a pointer [-Werror=array-parameter=]
   80 | int crypto_sign_ed25519_keypair(unsigned char *pk,
      |                                 ~~~~~~~~~~~~~~~^~
In file included from /builds/jjelen/libssh-mirror/src/external/ed25519.c:15:
/builds/jjelen/libssh-mirror/include/libssh/ed25519.h:46:48: note: previously declared as an array 'uint8_t[32]' {aka 'unsigned char[32]'}
   46 | int crypto_sign_ed25519_keypair(ed25519_pubkey pk, ed25519_privkey sk);
      |                                 ~~~~~~~~~~~~~~~^~
/builds/jjelen/libssh-mirror/src/external/ed25519.c:81:48: error: argument 2 of type 'unsigned char *' declared as a pointer [-Werror=array-parameter=]
   81 |                                 unsigned char *sk)
      |                                 ~~~~~~~~~~~~~~~^~
In file included from /builds/jjelen/libssh-mirror/src/external/ed25519.c:15:
/builds/jjelen/libssh-mirror/include/libssh/ed25519.h:46:68: note: previously declared as an array 'uint8_t[64]' {aka 'unsigned char[64]'}
   46 | int crypto_sign_ed25519_keypair(ed25519_pubkey pk, ed25519_privkey sk);
      |                                                    ~~~~~~~~~~~~~~~~^~
/builds/jjelen/libssh-mirror/src/external/ed25519.c:117:46: error: argument 5 of type 'const unsigned char *' declared as a pointer [-Werror=array-parameter=]
  117 |                         const unsigned char *sk)
      |                         ~~~~~~~~~~~~~~~~~~~~~^~
In file included from /builds/jjelen/libssh-mirror/src/external/ed25519.c:15:
/builds/jjelen/libssh-mirror/include/libssh/ed25519.h:61:27: note: previously declared as an array 'const uint8_t[64]' {aka 'const unsigned char[64]'}
   61 |     const ed25519_privkey sk);
      |     ~~~~~~~~~~~~~~~~~~~~~~^~
/builds/jjelen/libssh-mirror/src/external/ed25519.c:180:51: error: argument 5 of type 'const unsigned char *' declared as a pointer [-Werror=array-parameter=]
  180 |                              const unsigned char *pk)
      |                              ~~~~~~~~~~~~~~~~~~~~~^~
In file included from /builds/jjelen/libssh-mirror/src/external/ed25519.c:15:
/builds/jjelen/libssh-mirror/include/libssh/ed25519.h:76:26: note: previously declared as an array 'const uint8_t[32]' {aka 'const unsigned char[32]'}
   76 |     const ed25519_pubkey pk);
      |     ~~~~~~~~~~~~~~~~~~~~~^~

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Sahana Prasad <sahana@redhat.com>

src/external/ed25519.c

@@ -77,8 +77,8 @@ static void get_hram(unsigned char *hram,
 }
 
 
-int crypto_sign_ed25519_keypair(unsigned char *pk,
-                                unsigned char *sk)
+int crypto_sign_ed25519_keypair(ed25519_pubkey pk,
+                                ed25519_privkey sk)
 {
     sc25519 scsk;
     ge25519 gepk;
@@ -114,7 +114,7 @@ int crypto_sign_ed25519(unsigned char *sm,
                         uint64_t *smlen,
                         const unsigned char *m,
                         uint64_t mlen,
-                        const unsigned char *sk)
+                        const ed25519_privkey sk)
 {
     sc25519 sck, scs, scsk;
     ge25519 ger;
@@ -177,7 +177,7 @@ int crypto_sign_ed25519_open(unsigned char *m,
                              uint64_t *mlen,
                              const unsigned char *sm,
                              uint64_t smlen,
-                             const unsigned char *pk)
+                             const ed25519_pubkey pk)
 {
     unsigned int i;
     int ret;