BUG/MINOR: ssl: can't load ocsp files

246c024 ("MINOR: ssl: load the ocsp in/from the ckch") broke the loading
of OCSP files. The function ssl_sock_load_ocsp_response_from_file() was
not returning 0 upon success which lead to an error after the .ocsp was
read.
diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index 1a48e2a..1143065 100644
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -917,6 +917,7 @@
 	close(fd);
 	fd = -1;
 
+	ret = 0;
 end:
 	if (fd != -1)
 		close(fd);