Call sync() to guarantee blocks were released by unlink

Otherwise, the cached inode does not release the blocks which causes next
allocation for pinning fails.

Bug: 349270107
Change-Id: I4c2886683ea1949c1999e551a80b56dc37459dba
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>

fs_mgr/libfiemap/fiemap_writer.cpp

@@ -60,6 +60,7 @@ static_assert(sizeof(off_t) == sizeof(uint64_t));
 static inline void cleanup(const std::string& file_path, bool created) {
     if (created) {
         unlink(file_path.c_str());
+        sync();
     }
 }