[testsuite] Detect when devel-ignore-size.sh is unsupported

In PR27115, a failure of devel-ignore-size.sh is reported.

The test-case:
- tries to transform an executable
- checks that it didn't transform
- retries using --devel-ignore-size
- check that it did transform

The reported failure is in the second step.

Fix this by marking the test unsupported if the second step fails.

2021-01-04  Tom de Vries  <tdevries@suse.de>

	PR dwz/27115
	* testsuite/dwz.tests/devel-ignore-size.sh: If exec is transformed
	without --devel-ignore-size, mark unsupported.

---
 testsuite/dwz.tests/devel-ignore-size.sh | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/testsuite/dwz.tests/devel-ignore-size.sh b/testsuite/dwz.tests/devel-ignore-size.sh
index 5134043..78d28a2 100644
--- a/testsuite/dwz.tests/devel-ignore-size.sh
+++ b/testsuite/dwz.tests/devel-ignore-size.sh
@@ -12,7 +12,9 @@ cnt=$(readelf -wi 1 \
 	    | grep '(DW_TAG_partial_unit' \
 	    | wc -l)
 
-[ $cnt -eq 0 ]
+if [ $cnt -ne 0 ]; then
+    exit 77
+fi
 
 cp $execs/min 1