[COMMON] Fix function declarations bashisms

[COMMON] Fix function declarations bashisms

pointed out by checkbashisms.

$ mycmd=$(tox -e checkbashisms | grep "^possible .*'function' is useless
" | sed -e "s@^[^.]*\(.[^ ]*\) line \([0-9]*\) .*@sed -i -e '\2s/functio
n \\\([^ ()]*\\\) *(\\\?)\\\?/\\\1 ()/\' -e '\2s/(){/() {/' \1;@")

$ eval $mycmd

Issue-ID: OOM-2643
Signed-off-by: Guillaume Lambert <guillaume.lambert@orange.com>
Change-Id: Ic41c8ba8288b7a90db9f5775cd601c09ff2ab663