qemu-img incorrectly prints "qemu-img: Host floppy pass-through is deprecated"

qemu-img incorrectly prints this warning when you use /dev/fd/<NN> to pass in file descriptors.  A simple way to demonstrate this uses bash process substitution, so the following will only work if you are using bash as your shell:

$ qemu-img info <( cat /dev/null )
qemu-img: Host floppy pass-through is deprecated
Support for it will be removed in a future release.
qemu-img: Could not open '/dev/fd/63': Could not refresh total sector count: Illegal seek

The root cause is a bug in block/raw-posix.c:floppy_probe_device() where it thinks anything starting with /dev/fd is a floppy drive, which is not the case here:

http://git.qemu.org/?p=qemu.git;a=blob;f=block/raw-posix.c;h=cbe6574bf4da90a124436a40422dce3667da71e6;hb=HEAD#l2425