Revert "ext4: fix to check return value of freeze_bdev() in ext4_shutdown()"

This reverts commit 49d8396c56ccab57ecb82eac5f03d2ddbc6c5d5f.

Reason for revert: freeze_bdev() returns super_block*, not int causing a compile error.
                   Picking upstream change instead.

Change-Id: I1f13787df59d63c462630d386f5bdeaad7638ba5
1 file changed