libsnapshot: Fix crash in MakeXorBlockString test.

std::string doesn't like being initialized with negative values, so use
memset() instead.

Bug: 208944665
Test: vts_libsnapshot_test
Change-Id: I42a1a01fd9e59ffc9913c9df9f4bb8ab85113356

parent e8e5b5bb

fs_mgr/libsnapshot/snapshot_reader_test.cpp

+2 −2

Original line number	Diff line number	Diff line
		@@ -155,8 +155,8 @@ class OfflineSnapshotTest : public ::testing::Test {
		}

		std::string MakeXorBlockString() {
		std::string data(100, -1);
		data.resize(kBlockSize, 0);
		std::string data(kBlockSize, 0);
		memset(data.data(), 0xff, 100);
		return data;
		}