Somebody back in the mists of time decided that call_prom and rtas_call
should return longs even though both of those bits of firmware run in
32-bit mode and produce a 32-bit result.  To make life more interesting,
the 32-bit result gets zero-extended to 64 bits, which makes checking
for a -1 return value more complicated than it should be.

This patch changes call_prom and rtas_call to return an int, and makes
the corresponding changes to use ints for the variables used to hold
those return values. 

While I was doing this I finally got annoyed enough with the strings of
prom_print() and prom_print_hex() calls that we do to write a simple
prom_printf.  I deliberately didn't use snprintf because the execution
environment is weird at this point - we aren't running at the address we
are linked at just yet - and I didn't want to inflict that on any code
outside this file.  I also did a prom_debug() macro, which eliminated a
few ifdefs. 

There are also a bunch of other minor cleanups.  This patch makes very
few algorithmic changes but does get rid of a lot of casts.  :)

I have been running with this patch for a couple of weeks, and Anton has
tested it too.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>