uml: tidy process.c

Clean up arch/um/kernel/process.c:

- lots of return(x); -> return x; conversions

- a number of the small functions are either unused, in which case they are
  gone, along any declarations in a header, or could be made static.

- current_pid is ifdefed on CONFIG_MODE_TT and its declaration is ifdefed on
  both CONFIG_MODE_TT and UML_CONFIG_MODE_TT because we don't know whether
  it's being used in a userspace or kernel file.

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>

arch/um/include/um_malloc.h

@@ -11,7 +11,6 @@ extern void *um_kmalloc_atomic(int size);
 extern void kfree(const void *ptr);
 
 extern void *um_vmalloc(int size);
-extern void *um_vmalloc_atomic(int size);
 extern void vfree(void *ptr);
 
 #endif /* __UM_MALLOC_H__ */