pacstrap/arch-chroot: require root privileges to run

Suggested by Pierre. This makes sense since somewhere along the line,
pacman or mount are going to complain.

arch-chroot.in

@@ -16,6 +16,7 @@ if [[ -z $1 || $1 = @(-h|--help) ]]; then
   exit $(( $# ? 0 : 1 ))
 fi
 
+(( EUID == 0 )) || die 'This script must be run with root privileges'
 
 [[ -d $1 ]] || die "Can't create chroot on non-directory %s" "$1"
 

pacstrap.in

@@ -30,6 +30,8 @@ if [[ -z $1 || $1 = @(-h|--help) ]]; then
   exit $(( $# ? 0 : 1 ))
 fi
 
+(( EUID == 0 )) || die 'This script must be run with root privileges'
+
 while getopts ':dr:' flag; do
   case $flag in
     d)