pki_gcrypt: fix warnings for SSH_KEYTYPE_ED25519
pki_gcrypt: fix warnings for SSH_KEYTYPE_ED25519

Signed-off-by: Jon Simons <44f878afe53efc66b76772bd845eb65944ed8232@jonsimons.org>
Reviewed-by: Andreas Schneider <5be00ddc76278cf6077f5047ca3384a88460c671@cryptomilk.org>

mwgoldsmith/libssh,wangshawn/libssh,Distrotech/libssh,Distrotech/libssh,taikoo/libssh,kedazo/libssh,mwgoldsmith/ssh,kedazo/libssh,DouglasHeriot/libssh,mwgoldsmith/libssh,nviennot/libssh,mwgoldsmith/ssh,wangshawn/libssh,DouglasHeriot/libssh,robxu9/libssh,kedazo/libssh,taikoo/libssh,pouete/libssh,mwgoldsmith/libssh,mwgoldsmith/libssh,pouete/libssh,wangshawn/libssh,sebadoom/libssh,robxu9/libssh,DouglasHeriot/libssh,sebadoom/libssh,pouete/libssh,taikoo/libssh,pouete/libssh,kedazo/libssh,sebadoom/libssh,nviennot/libssh,Distrotech/libssh,DouglasHeriot/libssh,taikoo/libssh,Distrotech/libssh,wangshawn/libssh,nviennot/libssh,sebadoom/libssh,robxu9/libssh,mwgoldsmith/ssh,robxu9/libssh,nviennot/libssh,mwgoldsmith/ssh