FileSystemStore unit test: remove erased_set_get test

The "erased_set_get" test case deinits `FileSystemStore`, erases the
block device, and reinits `FileSystemStore`. This of course fails,
because `BlockDevice::erase()` removes all stored data including the
format of the `FileSystem` (middle layer), unless the particular type
of block device has a no-op erase implementation.

Note: Previously `HeapBlockDevice::erase()` was essentially a no-op
so this test case did not fail. We recently added the freeing of heap
memory and it uncovered the problem.

Author: LDong-Arm

storage/kvstore/filesystemstore/tests/UNITTESTS/FileSystemStore/moduletest.cpp

@@ -67,21 +67,6 @@ TEST_F(FileSystemStoreModuleTest, set_get)
     EXPECT_STREQ("data", buf);
 }
 
-TEST_F(FileSystemStoreModuleTest, erased_set_get)
-{
-    EXPECT_EQ(store->deinit(), MBED_SUCCESS);
-    EXPECT_EQ(heap.init(), MBED_SUCCESS);
-    EXPECT_EQ(heap.erase(0, heap.size()), MBED_SUCCESS);
-    EXPECT_EQ(heap.deinit(), MBED_SUCCESS);
-    EXPECT_EQ(store->init(), MBED_SUCCESS);
-    char buf[100];
-    size_t size;
-    EXPECT_EQ(store->set("key", "data", 5, 0), MBED_SUCCESS);
-    EXPECT_EQ(store->get("key", buf, 100, &size), MBED_SUCCESS);
-    EXPECT_EQ(size, 5);
-    EXPECT_STREQ("data", buf);
-}
-
 TEST_F(FileSystemStoreModuleTest, set_deinit_init_get)
 {
     char buf[100];