sb1000: fix a couple of indentation issues and remove assignment in if statements

There is an if statement and a return statement that are incorrectly
indented. Fix these.  Also replace the assignment-in-if statements
to assignment followed by an if to keep to the coding style.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>