vsprintf: associate the format state with the format pointer

vsprintf: associate the format state with the format pointer

The vsnprintf() code is written as a state machine as it walks the
format pointer, but for various historical reasons the state is oddly
named and was encoded as the 'type' field in the 'struct printf_spec'.

That naming came from the fact that the states used to not just encode
the state of the state machine, but also the various integer types that
would then be printed out.

Let's make the state machine more obvious, and actually call it 'state',
and associate it with the format pointer itself, rather than the
'printf_spec' that contains the currently decoded formatting specs.

This also removes the bit packing from printf_spec, which makes it much
easier on the compiler.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>