Fix ifeq_without_parens.mk

Also add a check for invalid testcases
diff --git a/testcase/ifeq_without_parens.mk b/testcase/ifeq_without_parens.mk
index dc679a3..41a9400 100644
--- a/testcase/ifeq_without_parens.mk
+++ b/testcase/ifeq_without_parens.mk
@@ -38,7 +38,7 @@
 RESULT += FAIL
 endif
 
-ifeq "VAR VAR" "$(VAR) $(VAR)"
+ifeq "var var" "$(VAR) $(VAR)"
 RESULT += PASS
 else
 RESULT += FAIL