bpf: fix possible endless loop in BPF map iteration

The _safe variant used here gets the next element before running the callback,
avoiding the endless loop condition.

Signed-off-by: Brandon Kammerdiener <brandon.kammerdiener@intel.com>
Link: https://lore.kernel.org/r/20250424153246.141677-2-brandon.kammerdiener@intel.com


Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Hou Tao <houtao1@huawei.com>