target: Fix MAINTENANCE_IN service action CDB checks to use lower 5 bits

This patch fixes the MAINTENANCE_IN service action type checks to only
look at the proper lower 5 bits of cdb byte 1. This addresses the case
where MI_REPORT_TARGET_PGS w/ extended header using the upper three bits of
cdb byte 1 was not processed correctly in transport_generic_cmd_sequencer,
as well as the three cases for standby, unavailable, and transition ALUA
primary access state checks.

Also add MAINTENANCE_IN to the excluded list in transport_generic_prepare_cdb()
to prevent the PARAMETER DATA FORMAT bits from being cleared.

Cc: Hannes Reinecke <[e-mail]>
Cc: Rob Evers <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: Roland Dreier <[e-mail]>
Signed-off-by: Nicholas Bellinger <[e-mail]>

drivers/target/target_core_alua.c

···
 	case RECEIVE_DIAGNOSTIC:
 	case SEND_DIAGNOSTIC:
 	case MAINTENANCE_IN:
-		switch (cdb[1]) {
+		switch (cdb[1] & 0x1f) {
 		case MI_REPORT_TARGET_PGS:
 			return 0;
 		default:
···
 	case INQUIRY:
 	case REPORT_LUNS:
 	case MAINTENANCE_IN:
-		switch (cdb[1]) {
+		switch (cdb[1] & 0x1f) {
 		case MI_REPORT_TARGET_PGS:
 			return 0;
 		default:
···
 	case INQUIRY:
 	case REPORT_LUNS:
 	case MAINTENANCE_IN:
-		switch (cdb[1]) {
+		switch (cdb[1] & 0x1f) {
 		case MI_REPORT_TARGET_PGS:
 			return 0;
 		default:

drivers/target/target_core_transport.c

···
 	case VERIFY_16: /* SBC - VRProtect */
 	case WRITE_VERIFY: /* SBC - VRProtect */
 	case WRITE_VERIFY_12: /* SBC - VRProtect */
+	case MAINTENANCE_IN: /* SPC - Parameter Data Format for SA RTPG */
 		break;
 	default:
 		cdb[1] &= 0x1f; /* clear logical unit number */
···
 			/*
 			 * Check for emulated MI_REPORT_TARGET_PGS.
 			 */
-			if (cdb[1] == MI_REPORT_TARGET_PGS &&
+			if ((cdb[1] & 0x1f) == MI_REPORT_TARGET_PGS &&
 			    su_dev->t10_alua.alua_type == SPC3_ALUA_EMULATED) {
 				cmd->execute_cmd =
 					target_emulate_report_target_port_groups;