gfs2: Always check the result of gfs2_rbm_from_block

When gfs2_rbm_from_block fails, the rbm it returns is undefined, so we
always want to make sure gfs2_rbm_from_block has succeeded before
looking at the rbm.

Signed-off-by: Andreas Gruenbacher <[email protected]>
Signed-off-by: Bob Peterson <[email protected]>
Reviewed-by: Steven Whitehouse <[email protected]>
1 file changed