error: Implement the warn and free Error functions

Implement warn_report_err() and warn_reportf_err() functions which
are the same as the error_report_err() and error_reportf_err()
functions except report a warning instead of an error.

Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <276ff93eadc0b01b8243cc61ffc331f77922c0d0.1499866456.git.alistair.francis@xilinx.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 9287cc5..4e91122 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2533,6 +2533,7 @@
 				error_setg_file_open|
 				error_set|
 				error_prepend|
+				warn_reportf_err|
 				error_reportf_err|
 				error_vreport|
 				warn_vreport|