include/linux/compiler-gcc.h: use __same_type() in __must_be_array()

We should use the __same_type() helper in __must_be_array().

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/compiler-gcc.h

@@ -35,8 +35,7 @@
     (typeof(ptr)) (__ptr + (off)); })
 
 /* &a[0] degrades to a pointer: a different type from an array */
-#define __must_be_array(a) \
-  BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))
+#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
 
 /*
  * Force always-inline if the user requests it so via the .config,