Check eap_get_name() return against NULL to silence static analyzer

This cannot really be NULL in practice since cred->eap_method would
point to a valid EAP method. Anyway, to avoid false positive from
analyzers, check the pointer explicitly before printing it.

Signed-off-by: Jouni Malinen <j@w1.fi>

wpa_supplicant/config_file.c

@@ -790,7 +790,8 @@ static void wpa_config_write_cred(FILE *f, struct wpa_cred *cred)
 		const char *name;
 		name = eap_get_name(cred->eap_method[0].vendor,
 				    cred->eap_method[0].method);
-		fprintf(f, "\teap=%s\n", name);
+		if (name)
+			fprintf(f, "\teap=%s\n", name);
 	}
 	if (cred->phase1)
 		fprintf(f, "\tphase1=\"%s\"\n", cred->phase1);