Renumber the ITER_* constants in uio.h

Renumber the ITER_* constants in linux/uio.h to make them consecutive
integers to make it easier for the compiler to optimise switch-statements
based on the iterator type.

Also replace all remaining AND-testing of iterator type with comparative
tests or switch-statements.

Signed-off-by: David Howells <dhowells@redhat.com>
2 files changed