abuild: abort build if md5 check fails

abuild

@@ -93,7 +93,7 @@ md5check() {
 	if [ "$(echo $source | wc -l)" -ne "$(echo $md5sums | wc -l)" ]; then
 		die "Number of md5sums does not correspond to number of sources"
 	fi
-	fetch
+	fetch || return 1
 	msg "Checking md5sums..."
 	cd "$srcdir" && echo "$md5sums" | md5sum -c 
 }
@@ -139,7 +139,7 @@ fetch() {
 # unpack the sources
 unpack() {
 	local u
-	md5check
+	md5check || return 1
 	mkdir -p "$srcdir"
 	for u in $source; do
 		local s="$SRCDEST/${u##*/}"	# $(basename $s)