Make R unittests pass failure to the Make system, otherwise failures are masked and won't be seen

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@12431 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Examples/test-suite/r/unittest.R

@@ -1,9 +1,17 @@
 unittest <- function (x,y) {
-if (x==y) print("PASS") 
-else print("FAIL") 
+  if (x==y) {
+    print("PASS") 
+  } else {
+    print("FAIL") 
+    stop("Test failed")
+  }
 }
 
 unittesttol <- function(x,y,z) {
-if (abs(x-y) < z) print("PASS")
-else print("FAIL")
-}
+  if (abs(x-y) < z) {
+    print("PASS")
+  } else {
+    print("FAIL")
+    stop("Test failed")
+  }
+}