staging: wlan-ng: use netdev_dbg over pr_debug

This patch replaces the usage of pr_debug() with netdev_dbg().
The change is made to enhance context-aware debugging,
improve code clarity, and maintain compatibility with established
network debugging practices. There were no functional code changes.
Signed-off-by: Calvince Otieno <calvncce@gmail.com>
Link: https://lore.kernel.org/r/ZS5RSsaNvOvshNj6@lab-ubuntuSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>