[PATCH v2 09/16] qapi/expr.py: rewrite check_if

[John Snow <jsnow@redhat.com>]

This is a only minor rewrite to address some minor style nits.  Don't
compare against the empty list to check for the empty condition, and
move the normalization forward to unify the check on the now-normalized
structure.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Tested-by: Cleber Rosa <crosa@redhat.com>
---
 scripts/qapi/expr.py | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py
index b393ccd30e92..4d4ee3daa002 100644
--- a/scripts/qapi/expr.py
+++ b/scripts/qapi/expr.py
@@ -143,15 +143,15 @@ def check_if_str(ifcond: object) -> None:
     ifcond = expr.get('if')
     if ifcond is None:
         return
-    if isinstance(ifcond, list):
-        if ifcond == []:
-            raise QAPISemError(
-                info, "'if' condition [] of %s is useless" % source)
-        for elt in ifcond:
-            check_if_str(elt)
-    else:
-        check_if_str(ifcond)
-        expr['if'] = [ifcond]
+
+    if not isinstance(ifcond, list):
+        ifcond = [ifcond]
+        expr['if'] = ifcond
+    if not ifcond:
+        raise QAPISemError(
+            info, "'if' condition [] of %s is useless" % source)
+    for elt in ifcond:
+        check_if_str(elt)
 
 
 def normalize_members(members: object) -> None:
-- 
2.26.2