[libc++] Fix forgotten fclose() in unit test

Thanks to Andrey Maksimov for the patch.
Differential Revision: https://reviews.llvm.org/D58732

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@355162 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/std/input.output/stream.buffers/streambuf/streambuf.virtuals/streambuf.virt.put/xsputn.PR14074.pass.cpp b/test/std/input.output/stream.buffers/streambuf/streambuf.virtuals/streambuf.virt.put/xsputn.PR14074.pass.cpp
index 1180008..d0b7b19 100644
--- a/test/std/input.output/stream.buffers/streambuf/streambuf.virtuals/streambuf.virt.put/xsputn.PR14074.pass.cpp
+++ b/test/std/input.output/stream.buffers/streambuf/streambuf.virtuals/streambuf.virt.put/xsputn.PR14074.pass.cpp
@@ -34,6 +34,7 @@
     std::size_t count = 0;
     while (std::fgetc(f) != EOF)
         ++count;
+    std::fclose(f);
     return count;
 }