dreport: add inventory persistent data to BMC dump

1.Run busctl command to get the inventory data and add to
BMC dump.
2.Add /var/lib/phosphor-inventory-manager data to BMC dump.

Tested:

root@perfrain86bmc:/tmp/test/obmcdump_00000000_1649923539# du -sh
phosphor-inventory-manager/
12.4M   phosphor-inventory-manager/
root@perfrain86bmc:/tmp/test/obmcdump_00000000_1649923539#

root@perfrain86bmc:/tmp/test/obmcdump_00000000_1649923539# ls -la inventory.log
-rw-r--r--    1 root     root             0 Apr 14 08:05 inventory.log

Signed-off-by: Marri Devender Rao <devenrao@in.ibm.com>
Change-Id: Iccb50e5f3a068fe3e13326326bfc5e66471b8b9e
diff --git a/tools/dreport.d/plugins.d/inventory b/tools/dreport.d/plugins.d/inventory
index 0fbdf4b..75873b2 100644
--- a/tools/dreport.d/plugins.d/inventory
+++ b/tools/dreport.d/plugins.d/inventory
@@ -4,7 +4,8 @@
 # @brief: Get the inventory information.
 #
 
-. $DREPORT_INCLUDE/functions
+# shellcheck disable=SC1091
+. "$DREPORT_INCLUDE"/functions
 
 desc="inventory"
 
@@ -16,4 +17,10 @@
 
 file_name="inventory.log"
 
-add_cmd_output "$command" "$file_name" "$desc"
+if ! add_cmd_output "$command" "$file_name" "$desc"; 
+then
+    inventory_dir="/var/lib/phosphor-inventory-manager"
+    if [ -d "$inventory_dir" ]; then
+        add_copy_file "$inventory_dir" "$desc"
+    fi
+fi