fix: make execution of voltctl use config instead of running it

* the old syntax of '${VOLTCTL_CONFIG}; voltctl ...' was first trying to
  execute the file set in ${VOLTCTL_CONFIG}, which is not possible since
  it is a configuration file
* although the current pipeline output looks like the VOLTCONF variable
  is passed somewhere else and does not need to be set explicitly here,
  lets keep it for now and just fix the syntax until we figure out where
  it is passed and why it was initially set like this (the old commit
  message which added this code does not mention any reason)
* use '-c' to explicitly pass the configuration file set in the variable
  '${VOLTCTL_CONFIG}' to voltctl

Signed-off-by: Jan Klare <jan.klare@bisdn.de>
Change-Id: I2d3ebeacbf1f389069dc05b3bfbf7fa716f9c83f
Signed-off-by: Jan Klare <jan.klare@bisdn.de>
diff --git a/tests/dt-workflow/Voltha_DT_PODTests.robot b/tests/dt-workflow/Voltha_DT_PODTests.robot
index 81bd468..b8ce023 100755
--- a/tests/dt-workflow/Voltha_DT_PODTests.robot
+++ b/tests/dt-workflow/Voltha_DT_PODTests.robot
@@ -322,7 +322,7 @@
         ${olt_serial_number}=    Get From Dictionary    ${olt_ids}[${I}]    sn
         ${olt_device_id}=    Get OLTDeviceID From OLT List    ${olt_serial_number}
         ${rc}    ${output}=    Run and Return Rc and Output
-        ...    ${VOLTCTL_CONFIG}; voltctl device disable ${olt_device_id}
+        ...    voltctl -c ${VOLTCTL_CONFIG} device disable ${olt_device_id}
         Should Be Equal As Integers    ${rc}    0
         Wait Until Keyword Succeeds    ${timeout}    5s    Validate OLT Device    DISABLED    UNKNOWN    REACHABLE
         ...    ${olt_serial_number}
@@ -420,7 +420,7 @@
         ${olt_serial_number}=    Get From Dictionary    ${olt_ids}[${I}]    sn
         ${olt_device_id}=    Get OLTDeviceID From OLT List    ${olt_serial_number}
         ${rc}    ${output}=    Run and Return Rc and Output
-        ...    ${VOLTCTL_CONFIG}; voltctl device disable ${olt_device_id}
+        ...    voltctl -c ${VOLTCTL_CONFIG} device disable ${olt_device_id}
         Should Be Equal As Integers    ${rc}    0
         Wait Until Keyword Succeeds    ${timeout}    5s    Validate OLT Device    DISABLED    UNKNOWN    REACHABLE
         ...    ${olt_serial_number}
diff --git a/tests/dt-workflow/Voltha_DT_PODTests_VGC.robot b/tests/dt-workflow/Voltha_DT_PODTests_VGC.robot
index 42d2a0d..62c792c 100755
--- a/tests/dt-workflow/Voltha_DT_PODTests_VGC.robot
+++ b/tests/dt-workflow/Voltha_DT_PODTests_VGC.robot
@@ -275,7 +275,7 @@
         ${olt_serial_number}=    Get From Dictionary    ${olt_ids}[${I}]    sn
         ${olt_device_id}=    Get OLTDeviceID From OLT List    ${olt_serial_number}
         ${rc}    ${output}=    Run and Return Rc and Output
-        ...    ${VOLTCTL_CONFIG}; voltctl device disable ${olt_device_id}
+        ...    voltctl -c ${VOLTCTL_CONFIG} device disable ${olt_device_id}
         Should Be Equal As Integers    ${rc}    0
         Wait Until Keyword Succeeds    ${timeout}    5s    Validate OLT Device    DISABLED    UNKNOWN    REACHABLE
         ...    ${olt_serial_number}
@@ -374,7 +374,7 @@
         ${olt_serial_number}=    Get From Dictionary    ${olt_ids}[${I}]    sn
         ${olt_device_id}=    Get OLTDeviceID From OLT List    ${olt_serial_number}
         ${rc}    ${output}=    Run and Return Rc and Output
-        ...    ${VOLTCTL_CONFIG}; voltctl device disable ${olt_device_id}
+        ...    voltctl -c ${VOLTCTL_CONFIG} device disable ${olt_device_id}
         Should Be Equal As Integers    ${rc}    0
         Wait Until Keyword Succeeds    ${timeout}    5s    Validate OLT Device    DISABLED    UNKNOWN    REACHABLE
         ...    ${olt_serial_number}