eap: Remove redundant error messages in .load_settings

A method's .check_settings method checks for inconsistent setting files
and prints readable errors so there's no need to do that again in
.load_settings, although at some point after removing the duplicate
error messages from the load_settings methods we agreed to keep minimum
checks that could cause a crash e.g. in a corner case like when the
setting file got modified between the check_settings and the
load_settings call.  Some error messages have been re-added to
load_settings after that (e.g. in
bb4e1ebd4f) but they're incomplete and not
useful so remove them.

src/eap-gtc.c

@@ -144,11 +144,8 @@ static bool eap_gtc_load_settings(struct eap_state *eap,
 									prefix);
 		password = l_settings_get_string(settings, "Security",
 								password_key);
-
-		if (!password) {
-			l_error("Property '%sPassword' is missing.", prefix);
+		if (!password)
 			return false;
-		}
 	}
 
 	gtc = l_new(struct eap_gtc_state, 1);

src/eap-md5.c

@@ -160,11 +160,8 @@ static bool eap_md5_load_settings(struct eap_state *eap,
 									prefix);
 		secret = l_settings_get_string(settings, "Security",
 								password_key);
-
-		if (!secret) {
-			l_error("Property '%sPassword' is missing.", prefix);
+		if (!secret)
 			return false;
-		}
 	}
 
 	md5 = l_new(struct eap_md5_state, 1);

src/eap-mschapv2.c

@@ -545,10 +545,8 @@ static bool eap_mschapv2_load_settings(struct eap_state *eap,
 
 	snprintf(setting, sizeof(setting), "%sIdentity", prefix);
 	state->user = l_settings_get_string(settings, "Security", setting);
-	if (!state->user) {
-		l_error("'%s' setting is missing", setting);
+	if (!state->user)
 		goto error;
-	}
 
 	state->user_len = strlen(state->user);
 
@@ -565,11 +563,8 @@ static bool eap_mschapv2_load_settings(struct eap_state *eap,
 
 		snprintf(setting, sizeof(setting), "%sPassword-Hash", prefix);
 		hash_str = l_settings_get_value(settings, "Security", setting);
-		if (!hash_str) {
-			l_error("Neither '%sPassword' or '%sPassword-Hash' "
-					"setting was provided", prefix, prefix);
+		if (!hash_str)
 			goto error;
-		}
 
 		tmp = l_util_from_hexstring(hash_str, &len);
 		memcpy(state->password_hash, tmp, 16);