fix(ubuntu): fix `defining function based on alias` error (#10560)

Fixes #10560

plugins/ubuntu/ubuntu.plugin.zsh

@@ -53,7 +53,7 @@ alias mydeb='time dpkg-buildpackage -rfakeroot -us -uc'
 # Usage: aar ppa:xxxxxx/xxxxxx [packagename]
 # If packagename is not given as 2nd argument the function will ask for it and guess the default by taking
 # the part after the / from the ppa name which is sometimes the right name for the package you want to install
-aar() {
+function aar() {
 	if [ -n "$2" ]; then
 		PACKAGE=$2
 	else
@@ -76,7 +76,7 @@ aar() {
 #   apt-history rollback
 #   apt-history list
 # Based On: https://linuxcommando.blogspot.com/2008/08/how-to-show-apt-log-history.html
-apt-history () {
+function apt-history() {
   case "$1" in
     install)
       zgrep --no-filename 'install ' $(ls -rt /var/log/dpkg*)
@@ -105,7 +105,7 @@ apt-history () {
 }
 
 # Kernel-package building shortcut
-kerndeb () {
+function kerndeb() {
   # temporarily unset MAKEFLAGS ( '-j3' will fail )
   MAKEFLAGS=$( print - $MAKEFLAGS | perl -pe 's/-j\s*[\d]+//g' )
   print '$MAKEFLAGS set to '"'$MAKEFLAGS'"