fixed compiler warnings issued by:

gcc 4.3
	curl.h gcc type-checking
	glibc with enabled FORTIFY_SOURCE checking

src/libstrongswan/utils.h

@@ -95,6 +95,11 @@
  */
 #define countof(array) (sizeof(array)/sizeof(array[0]))
 
+/**
+ * Ignore result of functions tagged with warn_unused_result attributes
+ */
+#define ignore_result(call) { if(call); }
+
 /**
  * Assign a function as a class method
  */