qemu-nbd: don't overlap long option values with short options

When defining values for long options, the normal practice is
to start numbering from 256, to avoid overlap with the range
of valid values for short options.
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

qemu-nbd.c

@@ -37,13 +37,13 @@
 #include <pthread.h>
 
 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
-#define QEMU_NBD_OPT_CACHE         1
-#define QEMU_NBD_OPT_AIO           2
-#define QEMU_NBD_OPT_DISCARD       3
-#define QEMU_NBD_OPT_DETECT_ZEROES 4
-#define QEMU_NBD_OPT_OBJECT        5
-#define QEMU_NBD_OPT_TLSCREDS      6
-#define QEMU_NBD_OPT_IMAGE_OPTS    7
+#define QEMU_NBD_OPT_CACHE         256
+#define QEMU_NBD_OPT_AIO           257
+#define QEMU_NBD_OPT_DISCARD       258
+#define QEMU_NBD_OPT_DETECT_ZEROES 259
+#define QEMU_NBD_OPT_OBJECT        260
+#define QEMU_NBD_OPT_TLSCREDS      261
+#define QEMU_NBD_OPT_IMAGE_OPTS    262
 
 static NBDExport *exp;
 static bool newproto;