[SPARK-26564] Fix wrong assertions and error messages for parameter checking

core/src/main/scala/org/apache/spark/SparkConf.scala

@@ -594,7 +594,7 @@ class SparkConf(loadDefaults: Boolean) extends Cloneable with Logging with Seria
     // If spark.executor.heartbeatInterval bigger than spark.network.timeout,
     // it will almost always cause ExecutorLostFailure. See SPARK-22754.
     require(executorTimeoutThresholdMs > executorHeartbeatIntervalMs, "The value of " +
-      s"spark.network.timeout=${executorTimeoutThresholdMs}ms must be no less than the value of " +
+      s"spark.network.timeout=${executorTimeoutThresholdMs}ms must be greater than the value of " +
       s"spark.executor.heartbeatInterval=${executorHeartbeatIntervalMs}ms.")
   }
 

mllib/src/main/scala/org/apache/spark/ml/optim/WeightedLeastSquares.scala

@@ -88,7 +88,7 @@ private[ml] class WeightedLeastSquares(
   require(regParam >= 0.0, s"regParam cannot be negative: $regParam")
   require(elasticNetParam >= 0.0 && elasticNetParam <= 1.0,
     s"elasticNetParam must be in [0, 1]: $elasticNetParam")
-  require(maxIter >= 0, s"maxIter must be a positive integer: $maxIter")
+  require(maxIter > 0, s"maxIter must be a positive integer: $maxIter")
   require(tol >= 0.0, s"tol must be >= 0, but was set to $tol")
 
   /**

sql/core/src/main/scala/org/apache/spark/sql/execution/exchange/BroadcastExchangeExec.scala

@@ -79,7 +79,7 @@ case class BroadcastExchangeExec(
           val (numRows, input) = child.executeCollectIterator()
           if (numRows >= 512000000) {
             throw new SparkException(
-              s"Cannot broadcast the table with more than 512 millions rows: $numRows rows")
+              s"Cannot broadcast the table with 512 million or more rows: $numRows rows")
           }
 
           val beforeBuild = System.nanoTime()

sql/core/src/main/scala/org/apache/spark/sql/execution/joins/HashedRelation.scala

@@ -413,7 +413,7 @@ private[execution] final class LongToUnsafeRowMap(val mm: TaskMemoryManager, cap
 
   private def init(): Unit = {
     if (mm != null) {
-      require(capacity < 512000000, "Cannot broadcast more than 512 millions rows")
+      require(capacity < 512000000, "Cannot broadcast 512 million or more rows")
       var n = 1
       while (n < capacity) n *= 2
       ensureAcquireMemory(n * 2L * 8 + (1 << 20))