param: add null statement to compiled-in module params

Add an unused struct declaration statement requiring a
terminating semicolon to the compile-in case to provoke an
error if __MODULE_INFO() is used without the terminating
semicolon. Previously MODULE_ALIAS("foo") (no semicolon)
compiled fine if MODULE was not selected.

Cc: Dan Carpenter <error27@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

include/linux/moduleparam.h

@@ -16,15 +16,17 @@
 /* Chosen so that structs with an unsigned long line up. */
 #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
 
-#ifdef MODULE
 #define ___module_cat(a,b) __mod_ ## a ## b
 #define __module_cat(a,b) ___module_cat(a,b)
+#ifdef MODULE
 #define __MODULE_INFO(tag, name, info)					  \
 static const char __module_cat(name,__LINE__)[]				  \
   __used __attribute__((section(".modinfo"), unused, aligned(1)))	  \
   = __stringify(tag) "=" info
 #else  /* !MODULE */
-#define __MODULE_INFO(tag, name, info)
+/* This struct is here for syntactic coherency, it is not used */
+#define __MODULE_INFO(tag, name, info)					  \
+  struct __module_cat(name,__LINE__) {}
 #endif
 #define __MODULE_PARM_TYPE(name, _type)					  \
   __MODULE_INFO(parmtype, name##type, #name ":" _type)