Fixed the return code for RAND_egd_bytes.

According to the documentation, the return code should be -1 when
RAND_status does not return 1.
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1886)

crypto/rand/rand_egd.c

@@ -228,10 +228,10 @@ int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes)
 
 int RAND_egd_bytes(const char *path, int bytes)
 {
-    int num, ret = 0;
+    int num, ret = -1;
 
     num = RAND_query_egd_bytes(path, NULL, bytes);
-    if (num < 1 || RAND_status() == 1)
+    if (RAND_status() == 1)
         ret = num;
  err:
     return (ret);