[SPARK-24908][R][STYLE] removing spaces to make lintr happy

## What changes were proposed in this pull request?

during my travails in porting spark builds to run on our centos worker, i managed to recreate (as best i could) the centos environment on our new ubuntu-testing machine.

while running my initial builds, lintr was crashing on some extraneous spaces in test_basic.R (see:  https://amplab.cs.berkeley.edu/jenkins/job/spark-master-test-sbt-hadoop-2.6-ubuntu-test/862/console)

after removing those spaces, the ubuntu build happily passed the lintr tests.

## How was this patch tested?

i then tested this against a modified spark-master-test-sbt-hadoop-2.6 build (see https://amplab.cs.berkeley.edu/jenkins/view/RISELab%20Infra/job/testing-spark-master-test-with-updated-R-crap/4/), which scp'ed a copy of test_basic.R in to the repo after the git clone.  everything seems to be working happily.

Author: shane knapp <[email protected]>

Closes apache#21864 from shaneknapp/fixing-R-lint-spacing.

R/pkg/inst/tests/testthat/test_basic.R

@@ -18,9 +18,9 @@
 context("basic tests for CRAN")
 
 test_that("create DataFrame from list or data.frame", {
-  tryCatch( checkJavaVersion(),
+  tryCatch(checkJavaVersion(),
             error = function(e) { skip("error on Java check") },
-            warning = function(e) { skip("warning on Java check") } )
+            warning = function(e) { skip("warning on Java check") })
 
   sparkR.session(master = sparkRTestMaster, enableHiveSupport = FALSE,
                  sparkConfig = sparkRTestConfig)
@@ -54,9 +54,9 @@ test_that("create DataFrame from list or data.frame", {
 })
 
 test_that("spark.glm and predict", {
-  tryCatch( checkJavaVersion(),
+  tryCatch(checkJavaVersion(),
             error = function(e) { skip("error on Java check") },
-            warning = function(e) { skip("warning on Java check") } )
+            warning = function(e) { skip("warning on Java check") })
 
   sparkR.session(master = sparkRTestMaster, enableHiveSupport = FALSE,
                  sparkConfig = sparkRTestConfig)