Use new methods search_file() and file_put_data().

Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>

src/hsm/cmd_keypair_gen.c

@@ -145,7 +145,7 @@ int cmd_keypair_gen() {
         return SW_EXEC_ERROR();
     }
     file_t *fpk = file_new((EE_CERTIFICATE_PREFIX << 8) | key_id);
-    ret = flash_write_data_to_file(fpk, res_APDU, res_APDU_size);
+    ret = file_put_data(fpk, res_APDU, res_APDU_size);
     if (ret != 0) {
         return SW_EXEC_ERROR();
     }