lorder: Tweak invalid file test.

Different implementations of `nm` have different ways of telling you
that your file is not a valid object or library, but they all seem to
have “not recognized” as a common substring.

MFC after:	1 week
Sponsored by:	Klara, Inc.
Reviewed by:	allanjude
Differential Revision:	https://reviews.freebsd.org/D44154

usr.bin/lorder/tests/lorder_test.sh

@@ -52,7 +52,7 @@ invalid_head() {
 }
 invalid_body() {
 	echo "not an object file" >invalid.o
-	atf_check -s not-exit:0 -e match:"File format not" -o empty \
+	atf_check -s not-exit:0 -e match:"not recognized" -o empty \
 		  lorder invalid.o
 }