fs/ext4: Remove jflag variable

The jflag variable serves almost no purpose.  Remove it.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Link: https://lore.kernel.org/r/20200528150003.828793-8-ira.weiny@intel.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>