mm/kmemleak: use IS_ERR_PCPU() for pointer in the percpu address space

mm/kmemleak: use IS_ERR_PCPU() for pointer in the percpu address space

Use IS_ERR_PCPU() instead of IS_ERR() for pointers in the percpu address
space.  The patch also fixes following sparse warnings:

kmemleak.c:1063:39: warning: cast removes address space '__percpu' of expression
kmemleak.c:1138:37: warning: cast removes address space '__percpu' of expression

Link: https://lkml.kernel.org/r/20240818210235.33481-2-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>