apparmor: Fix an error code in verify_table_headers()

We accidentally return a positive EPROTO instead of a negative -EPROTO.
Since 71 is not an error pointer, that means it eventually results in an
Oops in the caller.

Fixes: d901d6a298dc ("apparmor: dfa split verification of table headers")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

security/apparmor/match.c

@@ -198,7 +198,7 @@ out:
 static int verify_dfa(struct aa_dfa *dfa)
 {
 	size_t i, state_count, trans_count;
-	int error = EPROTO;
+	int error = -EPROTO;
 
 	state_count = dfa->tables[YYTD_ID_BASE]->td_lolen;
 	trans_count = dfa->tables[YYTD_ID_NXT]->td_lolen;