tst-rec-dlopen: Fix build fail due to missing inclusion of string.h

on S390, I get a compile error for dlfcn/tst-rec-dlopen.c:
tst-rec-dlopen.c: In function ‘malloc’:
tst-rec-dlopen.c:101:4: error: implicit declaration of function ‘strlen’ [-Werror=implicit-function-declaration]
    (void) write (STDOUT_FILENO, message, strlen (message));
    ^
tst-rec-dlopen.c:101:42: error: incompatible implicit declaration of built-in function ‘strlen’ [-Werror]
    (void) write (STDOUT_FILENO, message, strlen (message));
                                          ^
tst-rec-dlopen.c:112:42: error: incompatible implicit declaration of built-in function ‘strlen’ [-Werror]
    (void) write (STDOUT_FILENO, message, strlen (message));
                                          ^

This patch adds the missing "#include <string.h>" for strlen.

ChangeLog:

	* dlfcn/tst-rec-dlopen.c: Include string.h.

1 files changed, 4 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 84738f52ea..3cec387730 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2016-06-06  Stefan Liebler  <stli@linux.vnet.ibm.com>
+
+	* dlfcn/tst-rec-dlopen.c: Include string.h.
+
 2016-06-05  Paul Pluzhnikov  <ppluzhnikov@google.com>
 
 	* manual/install.texi: Remove mention of --without-tls