Move the REF_PRINT support from e_os.h to internal/refcount.h.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4188)
diff --git a/crypto/dsa/dsa_lib.c b/crypto/dsa/dsa_lib.c
index efd98c2..caaa65c 100644
--- a/crypto/dsa/dsa_lib.c
+++ b/crypto/dsa/dsa_lib.c
@@ -11,7 +11,7 @@
 
 #include <stdio.h>
 #include "internal/cryptlib.h"
-#include "e_os.h"
+#include "internal/refcount.h"
 #include <openssl/bn.h>
 #include "dsa_locl.h"
 #include <openssl/asn1.h>