security: mark expected switch fall-throughs and add a missing break

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warnings:

security/integrity/ima/ima_template_lib.c:85:10: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/integrity/ima/ima_policy.c:940:18: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/integrity/ima/ima_policy.c:943:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/integrity/ima/ima_policy.c:972:21: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/integrity/ima/ima_policy.c:974:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/smack/smack_lsm.c:3391:9: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/apparmor/domain.c:569:6: warning: this statement may fall through [-Wimplicit-fallthrough=]

Warning level 3 was used: -Wimplicit-fallthrough=3

Also, add a missing break statement to fix the following warning:

security/integrity/ima/ima_appraise.c:116:26: warning: this statement may fall through [-Wimplicit-fallthrough=]
Acked-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: NMimi Zohar <zohar@linux.ibm.com>
Signed-off-by: NJames Morris <james.morris@microsoft.com>

security/apparmor/domain.c

@@ -572,7 +572,7 @@ static struct aa_label *x_to_label(struct aa_profile *profile,
 			stack = NULL;
 			break;
 		}
-		/* fall through to X_NAME */
+		/* fall through - to X_NAME */
 	case AA_X_NAME:
 		if (xindex & AA_X_CHILD)
 			/* released by caller */

security/integrity/ima/ima_appraise.c

@@ -114,6 +114,7 @@ static void ima_set_cache_status(struct integrity_iint_cache *iint,
 		break;
 	case CREDS_CHECK:
 		iint->ima_creds_status = status;
+		break;
 	case FILE_CHECK:
 	case POST_SETATTR:
 		iint->ima_file_status = status;

security/integrity/ima/ima_policy.c

@@ -938,10 +938,12 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 		case Opt_uid_gt:
 		case Opt_euid_gt:
 			entry->uid_op = &uid_gt;
+			/* fall through */
 		case Opt_uid_lt:
 		case Opt_euid_lt:
 			if ((token == Opt_uid_lt) || (token == Opt_euid_lt))
 				entry->uid_op = &uid_lt;
+			/* fall through */
 		case Opt_uid_eq:
 		case Opt_euid_eq:
 			uid_token = (token == Opt_uid_eq) ||
@@ -970,9 +972,11 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 			break;
 		case Opt_fowner_gt:
 			entry->fowner_op = &uid_gt;
+			/* fall through */
 		case Opt_fowner_lt:
 			if (token == Opt_fowner_lt)
 				entry->fowner_op = &uid_lt;
+			/* fall through */
 		case Opt_fowner_eq:
 			ima_log_string_op(ab, "fowner", args[0].from,
 					  entry->fowner_op);

security/integrity/ima/ima_template_lib.c

@@ -83,6 +83,7 @@ static void ima_show_template_data_ascii(struct seq_file *m,
 		/* skip ':' and '\0' */
 		buf_ptr += 2;
 		buflen -= buf_ptr - field_data->data;
+		/* fall through */
 	case DATA_FMT_DIGEST:
 	case DATA_FMT_HEX:
 		if (!buflen)

security/smack/smack_lsm.c

@@ -3293,13 +3293,12 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
 		 */
 		final = &smack_known_star;
 		/*
-		 * Fall through.
-		 *
 		 * If a smack value has been set we want to use it,
 		 * but since tmpfs isn't giving us the opportunity
 		 * to set mount options simulate setting the
 		 * superblock default.
 		 */
+		/* Fall through */
 	default:
 		/*
 		 * This isn't an understood special case.