[SPARK-8548] [SPARKR] Remove the trailing whitespaces from the SparkR files

[[SPARK-8548] Remove the trailing whitespaces from the SparkR files - ASF JIRA](https://issues.apache.org/jira/browse/SPARK-8548)

- This is the result of `lint-r`
    https://gist.github.com/yu-iskw/0019b37a2c1167f33986

Author: Yu ISHIKAWA <yuu.ishikawa@gmail.com>

Closes #6945 from yu-iskw/SPARK-8548 and squashes the following commits:

0bd567a [Yu ISHIKAWA] [SPARK-8548][SparkR] Remove the trailing whitespaces from the SparkR files

(cherry picked from commit 44fa7df64d)
Signed-off-by: Shivaram Venkataraman <shivaram@cs.berkeley.edu>

R/pkg/R/generics.R

@@ -656,4 +656,3 @@ setGeneric("toRadians", function(x) { standardGeneric("toRadians") })
 #' @rdname column
 #' @export
 setGeneric("upper", function(x) { standardGeneric("upper") })
-

R/pkg/R/group.R

@@ -136,4 +136,3 @@ createMethods <- function() {
 }
 
 createMethods()
-

R/pkg/R/zzz.R

@@ -18,4 +18,3 @@
 .onLoad <- function(libname, pkgname) {
   sparkR.onLoad(libname, pkgname)
 }
-

R/pkg/inst/tests/test_binaryFile.R

@@ -87,4 +87,3 @@ test_that("saveAsObjectFile()/objectFile() works with multiple paths", {
   unlink(fileName1, recursive = TRUE)
   unlink(fileName2, recursive = TRUE)
 })
-

R/pkg/inst/tests/test_take.R

@@ -64,4 +64,3 @@ test_that("take() gives back the original elements in correct count and order",
   expect_true(length(take(numListRDD, 0)) == 0)
   expect_true(length(take(numVectorRDD, 0)) == 0)
 })
-

R/pkg/inst/tests/test_textFile.R

@@ -159,4 +159,3 @@ test_that("Pipelined operations on RDDs created using textFile", {
 
   unlink(fileName)
 })
-