fix: rubocop failures

Signed-off-by: Arjun Rajappa <arjun.rajappa@ibm.com>

Author: arjun-rajappa

lib/instana/trace/span.rb

@@ -87,13 +87,13 @@ def add_stack(span_stack_config: nil, stack: Kernel.caller)
 
       @attributes[:stack] = stack
                             .map do |call|
-                              file, line, *method = call.split(':')
+        file, line, *method = call.split(':')
 
-                              {
-                                c: file,
-                                n: line,
-                                m: method.join(' ')
-                              }
+        {
+          c: file,
+          n: line,
+          m: method.join(' ')
+        }
       end.take([limit, 40].min)
     end