Tidying in preparation for the segfault register dumping patch which follows.

void * pointers are changed to union uml_pt_regs *.  This makes the types
match reality, except in arch_fixup, which is changed to operate on a union
uml_pt_regs.  This fixes a bug in the call from segv_handler, which passes a
union uml_pt_regs, to segv, which expects to pass a struct sigcontext to
arch_fixup.

Whitespace and other style fixes.

There's also a errno printk fix.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>