Get some more LTP tests running, by making the tmp directory allowed for temporary files.

LibOS/shim/test/apps/ltp/manifest.template

@@ -26,3 +26,5 @@ sgx.trusted_files.libc = file:$(LIBCDIR)/libc.so.6
 sgx.trusted_files.libdl = file:$(LIBCDIR)/libdl.so.2
 sgx.trusted_files.libm = file:$(LIBCDIR)/libm.so.6
 sgx.trusted_files.libpthread = file:$(LIBCDIR)/libpthread.so.0
+
+sgx.allowed_files.tmp = file:/tmp