core: remove hardcoded 'init' from Log output

Until now the print procedure call in the Log_session_component
did contain a hardcoded 'init' string. Adding a method to filter
the session args to prefix the label and labelling the initial
Cpu_connection for the init-process enabled us to remove the
hardcoded string.

Fixes #789.

base/src/core/include/log_session_component.h

@@ -70,8 +70,7 @@ namespace Genode {
 					return len;
 				}
 
-				printf("[init%s%s] %s", strcmp(_label, "") == 0 ? "" : " -> ",
-				                        _label, string);
+				printf("[%s] %s", _label, string);
 
 				/* if last character of string was not a line break, add one */
 				if ((len > 0) && (string[len - 1] != '\n'))