misra: Fix crash in misra_9.py when struct type is unknown and there is string initialization (#5233)

addons/misra_9.py

@@ -255,7 +255,7 @@ class InitializerParser:
                 isFirstElement = False
                 isDesignated = True
 
-            elif self.token.isString and self.ed.isArray:
+            elif self.token.isString and self.ed and self.ed.isArray:
                 self.ed.setInitialized(isDesignated)
                 if self.token == self.token.astParent.astOperand1 and self.token.astParent.astOperand2:
                     self.token = self.token.astParent.astOperand2

addons/test/misra/crash7.c

@@ -0,0 +1,8 @@
+
+
+static const struct id3_frametype wordlist[] =
+{
+  {0, "Encryption method registration"},
+  {1, "Popularimeter"},
+};
+