When a zeroed out allocation is required, use calloc() rather than
malloc() followed by an explicit memset(). The result will be the
same, but using calloc() everywhere increases consistency in the
codebase and avoids the risk of subtle bugs when code is injected
between malloc and memset by accident.

Closes https://github.com/curl/curl/pull/2497

That means delete the timer.

Reported-by: Michael Kaufmann
Ref: #1253

In order to make the code style more uniform everywhere

... to please the new, slightly picker, checksrc.pl

All plain C examples now (mostly) adhere to the curl code style. While
they are only examples, they had diverted so much and contained all
sorts of different mixed code styles by now. Having them use a unified
style helps users and readability. Also, as they get copy-and-pasted
widely by users, making sure they're clean and nice is a good idea.

573 checksrc warnings were addressed.

... since it is never returned since a long while back.