firewire: nosy: Fix dma_free_coherent() size

firewire: nosy: Fix dma_free_coherent() size

It looks like the buffer allocated and mapped in add_card() is done
with size RCV_BUFFER_SIZE which is 16 KB and 4KB.

Fixes: 286468210d83 ("firewire: new driver: nosy - IEEE 1394 traffic sniffer")
Co-developed-by: Thomas Fourier <fourier.thomas@gmail.com>
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Co-developed-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/20251216165420.38355-2-fourier.thomas@gmail.com
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>