tmpfiles: rename --unsafe to --boot

As suggested by Kay, it is better to describe what is done,
not what might happen.
bootchart: Remove unneeded check for NULL

Directly before the changed line there is:

	while ((parent->next_ps && parent->pid != ps->ppid))
		parent = parent->next_ps;

which looks one element ahead of the list, hence we can rely on parent
being non null here.
If 'parent' were NULL at that while loop already, it would crash as we're
dereferencing 'parent' when checking for next_ps already.

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
sleep-config: Dereference pointer before check for NULL

This fixes a bug pointed out by http://css.csail.mit.edu/stack/
(Optimization-unstable code)
It is a similar fix as f146f5e159 (2013-12-30, core:
Forgot to dereference pointer when checking for NULL)

To explain this bug consider the following similar, but simpler code:
	if (!p)
		free(*p)

Assume the if condition evaluates to true, then we will access *p,
which means the compiler can assume p is a valid pointer, so it could
dereference p and use the value *p.
Assuming p as a valid pointer, !p will be false.
But initally we assumed the condition evaluates to true.

By this reasoning the optimizing compiler can deduce, we have dead code.
("The if will never be taken, as *p must be valid, because otherwise
accessing *p inside the if would segfault")

This led to an error message of the static code checker, so I checked the
code in question.

As we access *modes and *states before the check in the changed line of
this patch, I assume the line to be wrong and we actually wanted to check
for *modes and *states being both non null.