Fixing nullpointer

shiva/src/main/scala/nl/lumc/sasc/biopet/pipelines/shiva/ShivaVariantcalling.scala

@@ -97,6 +97,7 @@ class ShivaVariantcalling(val parent: Configurable) extends QScript
     cv.rod_priority_list = Some(callers.filter(_.mergeVcfResults).map(_.name).mkString(","))
     for (caller <- callers) {
       caller.inputBams = inputBams
+      caller.inputBqsrFiles = inputBqsrFiles
       caller.namePrefix = namePrefix
       caller.outputDir = new File(outputDir, caller.name)
       add(caller)

shiva/src/main/scala/nl/lumc/sasc/biopet/pipelines/shiva/variantcallers/Variantcaller.scala

@@ -33,7 +33,7 @@ trait Variantcaller extends QScript with BiopetQScript with Reference {
    * Map of samplename -> (preprocessed) bam file
    */
   var inputBams: Map[String, File] = _
-  var inputBqsrFiles: Map[String, File] = _
+  var inputBqsrFiles: Map[String, File] = Map()
 
   def init() = {}