OPatch Lsinventory Reports "OUI-67076 : OracleHomeInventory was not able to create a lock file" in Unix

Sometimes the command "opatch lsinventory" reports the error:
OUI-67076:OracleHomeInventory was not able to create a lock file, probably due to a previous failed OPatch Session. The loaded inventory might not show correctly what you have in the Oracle Home.

Cause
A previous "opatch apply" session failed and so a lock still exists on the local inventory.

Solution
1- Take a backup of $ORACLE_HOME/.patch_storage directory
$ cp -R $ORACLE_HOME/.patch_storage $ORACLE_HOME/.patch_storage_bkp

2- Remove $ORACLE_HOME/.patch_storage/patch_locked
$ rm $ORACLE_HOME/.patch_storage/patch_locked

3- Create empty file $ORACLE_HOME/.patch_storage/patch_free
$ touch $ORACLE_HOME/.patch_storage/patch_free

4- Verify that "opatch lsinventory" no longer reports the error
$ opatch lsinventory -detail