checkpatch: reversed logic with acpi test checks

Logic reversed: allowed list should just be ignored. Instead we
only take that into account :(

Fixes: e11b06a880 ("checkpatch: ignore allowed diff list")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20200602053614.54745-1-mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

scripts/checkpatch.pl

@@ -1267,7 +1267,7 @@ sub checkfilename {
         # files and when changing tests.
 	if ($name =~ m#^tests/data/acpi/# and not $name =~ m#^\.sh$#) {
 		$$acpi_testexpected = $name;
-	} elsif ($name =~ m#^tests/qtest/bios-tables-test-allowed-diff.h$#) {
+	} elsif ($name !~ m#^tests/qtest/bios-tables-test-allowed-diff.h$#) {
 		$$acpi_nontestexpected = $name;
 	}
 	if (defined $$acpi_testexpected and defined $$acpi_nontestexpected) {