linux-wandboard

jbd: Check return value of __getblk()

Fail journal creation if __getblk() returns NULL.  unlikely() is
added because it is called in a loop and we've been OK without
the check until now.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>