Systest hardbootme: Inventory diff file line numbers incorrect

To resolve false systest inventory difference, use Linux diff
instead of difflib. Python's difflib reports false differences.

Moved file diff code to the lib directory from syslib.

We want testing to continue even if SOL logging is not currently
available, so added  Ignore Error on Start SOL Console Logging.

Resolves openbmc/openbmc-test-automation#863
Change-Id: I04a412df584ca421e3ef129be9ae2452d7091d70
Signed-off-by: Steven Sombar <ssombar@us.ibm.com>
diff --git a/systest/htx_hardbootme_test.robot b/systest/htx_hardbootme_test.robot
index d1a1796..66fcfcb 100755
--- a/systest/htx_hardbootme_test.robot
+++ b/systest/htx_hardbootme_test.robot
@@ -26,19 +26,21 @@
 #                     This parameter is optional.  If not specified, an
 #                     initial inventory snapshot will be taken before
 #                     HTX startup.
-# INV_IGNORE_LIST     A comma-delimited list of colon-delimited pairs that
+# INV_IGNORE_LIST     A comma-delimited list of strings that
 #                     indicate what to ignore if there are inventory
-#                     differences.  For example, "processor:size,network:speed"
+#                     differences, (e.g., processor "size").
 #                     If differences are found during inventory checking
-#                     and those items are in this string, the
+#                     and those items are in this list, the
 #                     differences will be ignored.  This parameter is
 #                     optional.  If not specified the default value is
-#                     "processor:size".
+#                     "size".
 
 Resource        ../syslib/utils_os.robot
 Library         ../syslib/utils_keywords.py
+Library         ../lib/utils_files.py
 
-Suite Setup     Run Key  Start SOL Console Logging
+
+Suite Setup     Run Keyword And Ignore Error  Start SOL Console Logging
 Test Setup      Pre Test Case Execution
 Test Teardown   Post Test Case Execution
 
@@ -51,7 +53,7 @@
 ${json_diff_file_path}       ${EXECDIR}/os_inventory_diff.json
 ${last_inventory_file_path}  ${EMPTY}
 ${CHECK_INVENTORY}           True
-${INV_IGNORE_LIST}           processor:size
+${INV_IGNORE_LIST}           size
 ${PREV_INV_FILE_PATH}        ${EMPTY}
 
 
@@ -148,7 +150,7 @@
     # file1   A file that has an inventory snapshot in JSON format.
     # file2   A file that has an inventory snapshot, to compare with file1.
 
-    ${diff_rc}=  JSON_Inv_File_Diff_Check  ${file1}
+    ${diff_rc}=  File_Diff  ${file1}
      ...  ${file2}  ${json_diff_file_path}  ${INV_IGNORE_LIST}
     Run Keyword If  '${diff_rc}' != '${0}'
     ...  Report Inventory Mismatch  ${diff_rc}  ${json_diff_file_path}