Output the full searching path when cannot find an LKQL rule file

Author: HugoGGuerrier

lkql_checker/src/gnatcheck-rules-rule_table.adb

@@ -829,7 +829,7 @@ package body Gnatcheck.Rules.Rule_Table is
    begin
       --  Ensure that the provided rule file exists
       if not Is_Regular_File (Rule_File_Absolute_Path) then
-         Error ("can not locate LKQL rule file " & LKQL_RF_Name);
+         Error ("can not locate LKQL rule file " & Rule_File_Absolute_Path);
          Missing_Rule_File_Detected := True;
          return;
       end if;

testsuite/tests/gnatcheck_errors/invalid_lkql_rules_config/test.out

@@ -59,7 +59,7 @@ try "gnatcheck --help" for more information.
 Not existing file
 =================
 
-gnatcheck: error: can not locate LKQL rule file not_existing.lkql
+gnatcheck: error: can not locate LKQL rule file <working-dir>/not_existing.lkql
 gnatcheck: error: no rule to check specified
 try "gnatcheck --help" for more information.
 >>>program returned status code 2