Fix typo in 'already exiting LKQL rule file' error message

Author: HugoGGuerrier

lkql_checker/src/gnatcheck_main.adb

@@ -557,7 +557,7 @@ begin
       if Is_Regular_File (Default_LKQL_Rule_Options_File) then
          Error
            ("cannot emit the LKQL rule file, "
-            & Default_LKQL_Rule_Options_File & "already exists");
+            & Default_LKQL_Rule_Options_File & " already exists");
          OS_Exit (E_Error);
       end if;
 

testsuite/tests/gnatcheck_errors/already_existing_lkql_rule_file/rules.lkql

@@ -0,0 +1,3 @@
+val rules = @{
+    redundant_null_statements
+}

testsuite/tests/gnatcheck_errors/already_existing_lkql_rule_file/test.out

@@ -0,0 +1,8 @@
+testsuite_driver: No output file generated by gnatcheck
+gnatcheck: error: no existing file to process
+gnatcheck: error: cannot emit the LKQL rule file, <working-dir>/rules.lkql already exists
+>>>program returned status code 2
+testsuite_driver: Content of rules.lkql
+val rules = @{
+    redundant_null_statements
+}

testsuite/tests/gnatcheck_errors/already_existing_lkql_rule_file/test.yaml

@@ -0,0 +1,8 @@
+driver: gnatcheck
+description: Test the error message when using '--emit-lkql-rule-file' with an already existing rule file
+rules:
+  - +RGoto_Statements
+extra_args:
+  - --emit-lkql-rule-file
+post_python: "cat('rules.lkql', sort=False)"
+canonicalize_backslashes: True