[PATCH] checkpatch: avoid error on cover letter files

[Stefano Garzarella]

Running checkpatch on a directory that contains a cover letter reports
this error:

    Checking /tmp/tmpbnngauy3/0000-cover-letter.patch...
    ERROR: Does not appear to be a unified-diff format patch

    total: 1 errors, 0 warnings, 0 lines checked

Let's skip cover letter as it is already done in the Linux kernel.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 scripts/checkpatch.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index bd3faa154c..3c898f878a 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3005,7 +3005,7 @@ sub process {
                return 1;
        }
 
-       if (!$is_patch) {
+       if (!$is_patch && $filename !~ /cover-letter\.patch$/) {
                ERROR("Does not appear to be a unified-diff format patch\n");
        }
 
-- 
2.26.2