ktrace: Make -t t trace struct arrays as well as structs

Otherwise there is no specific -t option which captures struct arrays.

MFC after:	1 week

usr.bin/ktrace/ktrace.1

@@ -132,7 +132,7 @@ trace capability check failures
 .It Cm s
 trace signal processing
 .It Cm t
-trace various structures
+trace various structures and arrays of structures
 .It Cm u
 userland traces generated by
 .Xr utrace 2

usr.bin/ktrace/subr.c

@@ -70,7 +70,7 @@ getpoints(char *s)
 			facs |= KTRFAC_PSIG;
 			break;
 		case 't':
-			facs |= KTRFAC_STRUCT;
+			facs |= KTRFAC_STRUCT | KTRFAC_STRUCT_ARRAY;
 			break;
 		case 'u':
 			facs |= KTRFAC_USER;