Documentation/kcov: include types.h in the example

Patch series "kcov: PREEMPT_RT fixup + misc", v2.

The last patch in series is follow-up to address the PREEMPT_RT issue
within in kcov reported by Clark [1].  Patches 1-3 are smaller things that
I noticed while staring at it.  Patch 4 is small change which makes
replacement in #5 simpler / more obvious.

[1] https://lkml.kernel.org/r/20210809155909.333073de@theseus.lan

This patch (of 5):

The first example code has includes at the top, the following two
example share that part. The last example (remote coverage collection)
requires the linux/types.h header file due its __aligned_u64 usage.

Add the linux/types.h to the top most example and a comment that the
header files from above are required as it is done in the second
example.

Link: https://lkml.kernel.org/r/20210923164741.1859522-1-bigeasy@linutronix.de
Link: https://lore.kernel.org/r/20210830172627.267989-2-bigeasy@linutronix.de
Link: https://lkml.kernel.org/r/20210923164741.1859522-2-bigeasy@linutronix.de


Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Marco Elver <elver@google.com>
Tested-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Clark Williams <williams@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>