Remove hardcoded filepath

This does not mean that the configuration file will permanently stay on this folder/subfolder
structure.

It's just a way of letting things more easy to test and reproduce for now.

cmds/st.cmd

@@ -11,7 +11,7 @@ drvAsynIPPortConfigure("L0", "$(IPADDR):$(IPPORT) UDP", 0, 0, 1)
 #asynSetTraceIOMask( L0, -1, 0x4)
 #asynSetTraceInfoMask ( L0, -1, 0x9)
 
-RMMConfig("RMM", "L0", "/home/marcofilho/fe-vmm-tbl/cmds/config_file/lab_testbed.json", 0)
+RMMConfig("RMM", "L0", "$(IOCSH_TOP)/config_file/lab_testbed.json", 0)
 
 #VMMTblConfig("portName", ring, number_hybrids)
 VMMTblConfig("RMM", 0, 2)