Revert "make use of dependent on input array size"

This reverts commit 413980e93a.

modules/bamtools/split/main.nf

@@ -9,6 +9,7 @@ process BAMTOOLS_SPLIT {
 
     input:
     tuple val(meta), path(bam)
+    path(bam_list)
 
     output:
     tuple val(meta), path("*.bam"), emit: bam
@@ -20,22 +21,18 @@ process BAMTOOLS_SPLIT {
     script:
     def args = task.ext.args ?: ''
     def prefix = task.ext.prefix ?: "${meta.id}"
-
     def input_list = bam.collect{"-in $it"}.join(' ')
-    def stub_cmd = !args.contains("-stub") : " -stub ${prefix}" : ""
-
-    if (size(bam) > 1){
-        def bamtools_merge_cmd = "bamtools merge ${input_list} |"
-    } else {
-        def split_input = input_list
+    if (bam_list) {
+        input_list += " -list $bam_list"
+    }
+    if (!args.contains("-stub")) {
+        args += " -stub ${prefix}"
     }
 
-
     """
-    ${bamtools_merge_cmd} \\
-    bamtools split \\
-        $split_input \\
-        $stub_cmd \\
+    bamtools merge \\
+        ${input_list} \\
+    | bamtools split \\
         $args
 
     cat <<-END_VERSIONS > versions.yml