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

Fix newly found inconsistencies between assertions and messages

Author: sekikn

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/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 more than 512 millions rows")
       var n = 1
       while (n < capacity) n *= 2
       ensureAcquireMemory(n * 2L * 8 + (1 << 20))