fs/ocfs2/journal.h: add bits_wanted while calculating credits in ocfs2_calc_extend_cr...

fs/ocfs2/journal.h: add bits_wanted while calculating credits in ocfs2_calc_extend_credits

While adding extends to a file, the credits are calculated incorrectly
and if the requested clusters is more than one (or more because we used
a conservative limit) then we run out of journal credits and we hit an
assert in journalling code.

The function parameter bits_wanted variable was not used at all.

Signed-off-by: Goldwyn Rodrigues <[email protected]>
Reviewed-by: Jie Liu <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Mark Fasheh <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>