change output name for mergekmer collate

src/modules/mergekmer.nf

@@ -42,7 +42,7 @@ process COLLATEKMER {
     script:
     def args = task.ext.args ?: ''
     """
-    mergekmer --csv ${csv} --output ${csv[1].simpleName}.csv --collate
+    mergekmer --csv ${csv} --output fusion.csv --collate
 
 
     cat <<-END_VERSIONS > versions.yml