lightnvm: pblk: remove leftover testing function

A previous patch inadvertently left an unused test function in the
header, kill it.

Fixes: 8bd40020 ("lightnvm: pblk: cleanup unused and static functions")
Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/lightnvm/pblk.h

@@ -860,11 +860,6 @@ int pblk_rl_is_limit(struct pblk_rl *rl);
 int pblk_sysfs_init(struct gendisk *tdisk);
 void pblk_sysfs_exit(struct gendisk *tdisk);
 
-static inline void test(size_t a)
-{
-	a += 1;
-}
-
 static inline void *pblk_malloc(size_t size, int type, gfp_t flags)
 {
 	if (type == PBLK_KMALLOC_META)