utils: Fix broken sdk build on windows

Bug: 11324229
Change-Id: Ia50e79b5e2430faea77b0c98902e8e018fb9ceff
diff --git a/libutils/ProcessCallStack.cpp b/libutils/ProcessCallStack.cpp
index e202b9c..f9340c5 100644
--- a/libutils/ProcessCallStack.cpp
+++ b/libutils/ProcessCallStack.cpp
@@ -140,6 +140,7 @@
     clear();
 
     // Get current time.
+#ifndef USE_MINGW
     {
         time_t t = time(NULL);
         struct tm tm;
@@ -193,6 +194,7 @@
         ALOGE("%s: Failed to readdir from %s (errno = %d, '%s')",
               __FUNCTION__, PATH_SELF_TASK, -code, strerror(code));
     }
+#endif
 
     closedir(dp);
 }