qemu-pr-helper: miscellaneous fixes

1) Return a generic sense if TEST UNIT READY does not provide one;

2) Fix two mistakes in copying from the spec.

Cc: qemu-stable@nongnu.org
Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

scsi/utils.c

@@ -211,6 +211,16 @@ const struct SCSISense sense_code_LUN_COMM_FAILURE = {
     .key = ABORTED_COMMAND, .asc = 0x08, .ascq = 0x00
 };
 
+/* Medium Error, Unrecovered read error */
+const struct SCSISense sense_code_READ_ERROR = {
+    .key = MEDIUM_ERROR, .asc = 0x11, .ascq = 0x00
+};
+
+/* Not ready, Cause not reportable */
+const struct SCSISense sense_code_NOT_READY = {
+    .key = NOT_READY, .asc = 0x04, .ascq = 0x00
+};
+
 /* Unit attention, Capacity data has changed */
 const struct SCSISense sense_code_CAPACITY_CHANGED = {
     .key = UNIT_ATTENTION, .asc = 0x2a, .ascq = 0x09