components/*.c: include slstatus.h

this gives the compiler a chance to check weather the prototype and
definiton matches or not, which would catch issues like 3c47701.

components/ip.c

@@ -12,6 +12,7 @@
 #endif
 
 #include "../util.h"
+#include "../slstatus.h"
 
 static const char *
 ip(const char *interface, unsigned short sa_family)