(c-guess-basic-syntax): prevent a macro call inside a struct being

recognised as a K&R argument.

lisp/progmodes/cc-engine.el

@@ -8296,6 +8296,7 @@ comment at the start of cc-engine.el for more info."
 
 	   ;; CASE 5H: we could be looking at subsequent knr-argdecls
 	   ((and c-recognize-knr-p
+		 (not containing-sexp)	; can't be knr inside braces.
 		 (not (eq char-before-ip ?}))
 		 (save-excursion
 		   (setq placeholder (cdr (c-beginning-of-decl-1 lim)))