[SPARK-18326][SPARKR][ML] Review SparkR ML wrappers API for 2.1

## What changes were proposed in this pull request?
Reviewing SparkR ML wrappers API for 2.1 release, mainly two issues:
* Remove ```probabilityCol``` from the argument list of ```spark.logit``` and ```spark.randomForest```. Since it was used when making prediction and should be an argument of ```predict```, and we will work on this at [SPARK-18618](https://issues.apache.org/jira/browse/SPARK-18618) in the next release cycle.
* Fix ```spark.als``` params to make it consistent with MLlib.

## How was this patch tested?
Existing tests.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #16169 from yanboliang/spark-18326.

1 files changed, 2 insertions, 2 deletions

diff --git a/R/pkg/inst/tests/testthat/test_mllib.R b/R/pkg/inst/tests/testthat/test_mllib.R
index 4758e40e41..53833ee2f3 100644
--- a/R/pkg/inst/tests/testthat/test_mllib.R
+++ b/R/pkg/inst/tests/testthat/test_mllib.R
@@ -926,10 +926,10 @@ test_that("spark.posterior and spark.perplexity", {
 
 test_that("spark.als", {
   data <- list(list(0, 0, 4.0), list(0, 1, 2.0), list(1, 1, 3.0), list(1, 2, 4.0),
-  list(2, 1, 1.0), list(2, 2, 5.0))
+               list(2, 1, 1.0), list(2, 2, 5.0))
   df <- createDataFrame(data, c("user", "item", "score"))
   model <- spark.als(df, ratingCol = "score", userCol = "user", itemCol = "item",
-  rank = 10, maxIter = 5, seed = 0, reg = 0.1)
+                     rank = 10, maxIter = 5, seed = 0, regParam = 0.1)
   stats <- summary(model)
   expect_equal(stats$rank, 10)
   test <- createDataFrame(list(list(0, 2), list(1, 0), list(2, 0)), c("user", "item"))