[SPARK-8637] [SPARKR] [HOTFIX] Fix packages argument, sparkSubmitBinName

cc cafreeman

Author: Shivaram Venkataraman <shivaram@cs.berkeley.edu>

Closes #7022 from shivaram/sparkr-init-hotfix and squashes the following commits:

9178d15 [Shivaram Venkataraman] Fix packages argument, sparkSubmitBinName

R/pkg/R/client.R

@@ -57,7 +57,7 @@ generateSparkSubmitArgs <- function(args, sparkHome, jars, sparkSubmitOpts, pack
 }
 
 launchBackend <- function(args, sparkHome, jars, sparkSubmitOpts, packages) {
-  sparkSubmitBin <- determineSparkSubmitBin()
+  sparkSubmitBinName <- determineSparkSubmitBin()
   if (sparkHome != "") {
     sparkSubmitBin <- file.path(sparkHome, "bin", sparkSubmitBinName)
   } else {

R/pkg/R/sparkR.R

@@ -132,7 +132,7 @@ sparkR.init <- function(
         sparkHome = sparkHome,
         jars = jars,
         sparkSubmitOpts = Sys.getenv("SPARKR_SUBMIT_ARGS", "sparkr-shell"),
-        sparkPackages = sparkPackages)
+        packages = sparkPackages)
     # wait atmost 100 seconds for JVM to launch
     wait <- 0.1
     for (i in 1:25) {