Fix for SSH connection loss after FFDC in boot_devices suite.

This changes includes:
  - Open SSH connection before each test case run.
  - Close SSH connection post each test case run.
  - Added pre and post test cases execution keywords.
  - Removed suite setup and teardown.

Resolves openbmc/openbmc-test-automation#450

Change-Id: Ibb44b0247cb31f63e670593cdb963b963f36d86f
Signed-off-by: Sweta Potthuri <spotthur@in.ibm.com>
diff --git a/tests/test_boot_devices.robot b/tests/test_boot_devices.robot
index 4a17741..5459dc0 100644
--- a/tests/test_boot_devices.robot
+++ b/tests/test_boot_devices.robot
@@ -7,10 +7,9 @@
 Resource        ../lib/openbmc_ffdc.robot
 Resource        ../lib/utils.robot
 
-Suite Setup     Open Connection And Log In
-Suite Teardown  Close All Connections
-Test Setup      Initialize DBUS cmd   "boot_flags"
-Test Teardown   FFDC On Test Case Fail
+Test Setup      Pre Test Case Execution
+Test Teardown   Post Test Case Execution
+
 
 *** Variables ***
 
@@ -190,3 +189,15 @@
     [Arguments]  ${uri}  ${parm}
     ${output}=  Read Attribute  ${uri}  ${parm}
     Set Test Variable  ${OUTPUT}  ${output}
+
+Pre Test Case Execution
+   [Documentation]  Do the pre test setup.
+
+   Open Connection And Log In
+   Initialize DBUS cmd  "boot_flags"
+
+Post Test Case Execution
+   [Documentation]  Do the post test teardown.
+
+   FFDC On Test Case Fail
+   Close All Connections