If we get a failure at the first decompressor init (i = 0),
the clean up while loop could enter infinite loop due to wrong while
check. Check the value of i now to see if we need any clean up at all.
Fixes: 5a7cce827ee9 ("erofs: refine z_erofs_{init,exit}_subsystem()")
Reported-by: liujinbao1 <liujinbao1@xxxxxxxxxx>
Signed-off-by: Sandeep Dhavale <dhavale@xxxxxxxxxx>