We had nested spinlocks using the same flags variable, but it turns out
that we don't need the nested locks at all (the lock protects a static
buffer that we aren't using here), so just remove the extra locks.

Spotted by Alexey Dobriyan.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

So the iSeries console will be faster since it can send up to 200 bytes at
a time to the Hypervisor.  This only affects the tty part of the console,
the console writes are still in 16 byte lots.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>

This driver uses the hvc_console.c infrastructure that is used by the
pSeries virtual and RTAS consoles.  This will allow us to make viocons.c
obsolete and is another step along the way to a combined kernel (as
viocons could not coexist with CONFIG_VT).
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>