zdtm: fix decode_flav()

decode_flav() was doing 'if i in flavors:' where 'i' was an integer but
the keys from the flavors dict are strings 'h', 'ns' and 'uns'.
Signed-off-by: Adrian Reber <areber@redhat.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

test/zdtm.py

@@ -291,10 +291,10 @@ def encode_flav(f):
 
 
 def decode_flav(i):
-	i = i - 128
-	if i in flavors:
+	try:
 		return flavors.keys()[i - 128]
-	return "unknown"
+	except:
+		return "unknown"
 
 
 def tail(path):