raw-posix: Don't use file name for host_cdrom detection on Linux

On Linux, we have code to detect CD-ROMs using an ioctl. We shouldn't lose
anything but false positives by removing the check for a /dev/cd* path.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
(cherry picked from commit 897804d6)

block/raw-posix.c

@@ -1154,9 +1154,6 @@ static int cdrom_probe_device(const char *filename)
     int fd, ret;
     int prio = 0;
 
-    if (strstart(filename, "/dev/cd", NULL))
-        prio = 50;
-
     fd = open(filename, O_RDONLY | O_NONBLOCK);
     if (fd < 0) {
         goto out;