remove unecessary code

Signed-off-by: Augusto Berndt <augusto.berndt@precisioninno.com>

Author: gudeh

flow/scripts/cts.tcl

@@ -46,7 +46,7 @@ set_placement_padding -global \
   -left $::env(CELL_PAD_IN_SITES_DETAIL_PLACEMENT) \
   -right $::env(CELL_PAD_IN_SITES_DETAIL_PLACEMENT)
 
-if { [env_var_exists_and_non_empty USE_NEGOTIATION] && $::env(USE_NEGOTIATION) } {
+if { $::env(USE_NEGOTIATION) } {
   set result [catch { log_cmd detailed_placement -use_negotiation } msg]
 } else {
   set result [catch { log_cmd detailed_placement } msg]
@@ -74,7 +74,7 @@ if { !$::env(SKIP_CTS_REPAIR_TIMING) } {
     run_lec_test 4_rsz 4_before_rsz_lec.v 4_after_rsz_lec.v
   }
 
-  if { [env_var_exists_and_non_empty USE_NEGOTIATION] && $::env(USE_NEGOTIATION) } {
+  if { $::env(USE_NEGOTIATION) } {
     set result [catch { log_cmd detailed_placement -use_negotiation } msg]
   } else {
     set result [catch { log_cmd detailed_placement } msg]

flow/scripts/detail_place.tcl

@@ -15,7 +15,7 @@ proc do_dpl { } {
   set_placement_padding -global \
     -left $::env(CELL_PAD_IN_SITES_DETAIL_PLACEMENT) \
     -right $::env(CELL_PAD_IN_SITES_DETAIL_PLACEMENT)
-  if { [env_var_exists_and_non_empty USE_NEGOTIATION] && $::env(USE_NEGOTIATION) } {
+  if { $::env(USE_NEGOTIATION) } {
     log_cmd detailed_placement -use_negotiation {*}[env_var_or_empty DETAIL_PLACEMENT_ARGS]
   } else {
     log_cmd detailed_placement {*}[env_var_or_empty DETAIL_PLACEMENT_ARGS]

flow/scripts/global_route.tcl

@@ -62,7 +62,7 @@ proc global_route_helper { } {
     # Running DPL to fix overlapped instances
     # Run to get modified net by DPL
     log_cmd global_route -start_incremental
-    if { [env_var_exists_and_non_empty USE_NEGOTIATION] && $::env(USE_NEGOTIATION) } {
+    if { $::env(USE_NEGOTIATION) } {
       log_cmd detailed_placement -use_negotiation
     } else {
       log_cmd detailed_placement
@@ -84,7 +84,7 @@ proc global_route_helper { } {
     # Running DPL to fix overlapped instances
     # Run to get modified net by DPL
     log_cmd global_route -start_incremental
-    if { [env_var_exists_and_non_empty USE_NEGOTIATION] && $::env(USE_NEGOTIATION) } {
+    if { $::env(USE_NEGOTIATION) } {
       log_cmd detailed_placement -use_negotiation
     } else {
       log_cmd detailed_placement