Iterators aren't necessary as you can just grab the first entry and delete
it until no entries left.

Link: http://lkml.kernel.org/r/20171121191121.GA20757@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>