fix define.mk

run shell command per each line after eval.
use %q for multiline value. otherwise runtest.rb confuses the output.
diff --git a/parser.go b/parser.go
index cd3c8c7..7079bf2 100644
--- a/parser.go
+++ b/parser.go
@@ -100,7 +100,7 @@
 }
 
 func (p *parser) parseAssign(line []byte, sep, esep int) AST {
-	Log("parseAssign %s %s", line, line[sep:esep])
+	Log("parseAssign %q op:%q", line, line[sep:esep])
 	ast := &AssignAST{
 		lhs: string(bytes.TrimSpace(line[:sep])),
 		rhs: string(bytes.TrimLeft(line[esep:], " \t")),