HADOOP-12952. BUILDING example of zero-docs dist should skip javadocs. Contributed by Steve Loughran.

(cherry picked from commit a107cee14bb5446057da81d1c95d7fffd759e497)

BUILDING.txt

@@ -224,7 +224,7 @@ Building distributions:
 
 Create binary distribution without native code and without documentation:
 
-  $ mvn package -Pdist -DskipTests -Dtar
+  $ mvn package -Pdist -DskipTests -Dtar -Dmaven.javadoc.skip=true
 
 Create binary distribution with native code and with documentation: