romcc: Use UNIX line endings in linux tests

This makes it easier to check the output against a reference output.

Change-Id: I9c7ae538b708399a5cadd18e498618d7480d240f
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/14276
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Martin Roth <martinroth@google.com>

util/romcc/tests/linux_test1.c

@@ -2,7 +2,7 @@
 
 static void main(void)
 {
-	static const char msg[] = "hello world\r\n";
+	static const char msg[] = "hello world\n";
 	write(STDOUT_FILENO, msg, sizeof(msg));
 	_exit(0);
 }