dm: rearrange dm_wq_work
dm: rearrange dm_wq_work

Refactor dm_wq_work() to make later patch more readable.

Signed-off-by: Alasdair G Kergon <620085386a2c64ec2f1d43bef997c15003f13da2@redhat.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas