[Qemu-block] [PATCH 1/3] iotests.py: improve verify_image_format helper

[Vladimir Sementsov-Ogievskiy]

Add an assert (we don't want set both arguments) and remove
duplication.

Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
 tests/qemu-iotests/iotests.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index b5d7945..83c454d 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -532,9 +532,9 @@ def notrun(reason):
     sys.exit(0)
 
 def verify_image_format(supported_fmts=[], unsupported_fmts=[]):
-    if supported_fmts and (imgfmt not in supported_fmts):
-        notrun('not suitable for this image format: %s' % imgfmt)
-    if unsupported_fmts and (imgfmt in unsupported_fmts):
+    assert not (supported_fmts and unsupported_fmts)
+    not_sup = supported_fmts and (imgfmt not in supported_fmts)
+    if not_sup or (imgfmt in unsupported_fmts):
         notrun('not suitable for this image format: %s' % imgfmt)
 
 def verify_platform(supported_oses=['linux']):
-- 
2.7.4