block: remove unwanted semicolons

Since those defined functions require additional semicolon
from the caller, they could cause potential syntax errors
when used in if-else statements.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>