Replace cases of time_t with mbedtls_time_t

Signed-off-by: Ben Taylor <ben.taylor@linaro.org>
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 37e4259..75c59a9 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -3178,7 +3178,7 @@
     start = MBEDTLS_GET_UINT64_BE(p, 0);
     p += 8;
 
-    session->start = (time_t) start;
+    session->start = (mbedtls_time_t) start;
 #endif /* MBEDTLS_HAVE_TIME */
 
     /*
diff --git a/programs/ssl/ssl_context_info.c b/programs/ssl/ssl_context_info.c
index 7bcd50f..46875ec 100644
--- a/programs/ssl/ssl_context_info.c
+++ b/programs/ssl/ssl_context_info.c
@@ -277,7 +277,7 @@
 {
 #if defined(MBEDTLS_HAVE_TIME)
     char buf[20];
-    struct tm *t = gmtime((time_t *) time);
+    struct tm *t = gmtime((mbedtls_time_t *) time);
     static const char format[] = "%Y-%m-%d %H:%M:%S";
     if (NULL != t) {
         strftime(buf, sizeof(buf), format, t);
diff --git a/programs/test/udp_proxy.c b/programs/test/udp_proxy.c
index 1c52990..efa003d 100644
--- a/programs/test/udp_proxy.c
+++ b/programs/test/udp_proxy.c
@@ -25,7 +25,6 @@
 #if defined(MBEDTLS_HAVE_TIME)
 #include <time.h>
 #define mbedtls_time            time
-#define mbedtls_time_t          time_t
 #endif
 #define mbedtls_printf          printf
 #define mbedtls_calloc          calloc