dm cache: avoid conflicting remove_mapping() in mq policy

dm cache: avoid conflicting remove_mapping() in mq policy

On sparc32, which includes <linux/swap.h> from <asm/pgtable_32.h>:

drivers/md/dm-cache-policy-mq.c:962:13: error: conflicting types for 'remove_mapping'
include/linux/swap.h:285:12: note: previous declaration of 'remove_mapping' was here

As mq_remove_mapping() already exists, and the local remove_mapping() is
used only once, inline it manually to avoid the conflict.

Signed-off-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>
Signed-off-by: Alasdair Kergon <[email protected]>
Acked-by: Joe Thornber <[email protected]>