Fix-up coding style

The .clang-format is a symlink to ../init/.clang-format, which is merged
recently. As init is the major user of fs_mgr, it's better to keep the
style consistent.

Only recent newly-added files written by me are formatted. For other
files, let's format them gradually to keep 'git blame' intact.

Bug: None
Test: Device can boot with AVB

Change-Id: I5c72f23b38534d5bcef3e4f9f0f477fa40496433