abuild: fix doc hardlinks replaced nondeterministic

default_doc replaces hardlinks with symlinks. Which files are symlinked
and which file is replaced was depending on the order of the files found
by find(1) which is not deterministic.

abuild.in

@@ -1991,7 +1991,7 @@ default_doc() {
 	[ -d "$mandir" ] && find "$mandir" -type f \
 		-a \( -name \*.[0-8n] -o -name \*.[0-8][a-z]* \) \
 		-a \! \( -name '*.gz' -o -name '*.bz2' -o -name '*.xz' \) \
-		-exec stat -c "%i %n" \{\} \+ | while read inode name; do
+		-exec stat -c "%i %n" \{\} \+ | sort | while read inode name; do
 
 		# Skip hardlinks removed in last iteration.
 		[ -f "$name" ] || continue