lib: Drop intermediary return variables

lib: Drop intermediary return variables

In a few places we declare a variable (which is optionally
followed by a code not touching it) then set the variable to a
value and return the variable immediately. It's obvious that the
variable is needless and the value can be returned directly
instead.

This patch was generated using this semantic patch:

  @@
  type T;
  identifier ret;
  expression E;
  @@
  - T ret;
  ... when != ret
      when strict
  - ret = E;
  - return ret;
  + return E;

After that I fixed couple of formatting issues because coccinelle
formatted some lines differently than our coding style.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>