ape: improve assert macro

in a statement such as:

if(expr)
	assert(a);
else
	assert(b);

the previous definition of assert would fail to compile, as the else
would be dangling.  with a ternary expression, this construct works
fine.

sys/include/ape/assert.h

@@ -13,5 +13,5 @@ extern void _assert(char *, unsigned);
 #ifdef __cplusplus
 }
 #endif
-#define assert(e) {if(!(e))_assert(__FILE__, __LINE__);}
+#define assert(e) ((e) ? (void)0 : _assert(__FILE__, __LINE__))
 #endif /* NDEBUG */