serial: kgdb_nmi: Improve console integration with KDB I/O
serial: kgdb_nmi: Improve console integration with KDB I/O

kgdb_nmi_tty_enabled is used for two unrelated purposes, namely to
suppress normal TTY input handling and to suppress console output
(although it has no effect at all on TTY output). A much better way to
handle muting the console is to not have to mute it in the first place!
That's what this patch does.

Signed-off-by: Daniel Thompson <4421c302a8f2019ff02452a16ddbdd37770f814c@linaro.org>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs