bpf: Remove unused MEM_ALLOC | PTR_TRUSTED checks

The plan is to supposedly tag everything with PTR_TRUSTED eventually,
however those changes should bring in their respective code, instead
of leaving it around right now. It is arguable whether PTR_TRUSTED is
required for all types, when it's only use case is making PTR_TO_BTF_ID
a bit stronger, while all other types are trusted by default.

Hence, just drop the two instances which do not occur in the verifier
for now to avoid reader confusion.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230221200646.2500777-5-memxor@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

kernel/bpf/verifier.c

@@ -6656,7 +6656,6 @@ int check_func_arg_reg_off(struct bpf_verifier_env *env,
 	case PTR_TO_BTF_ID | MEM_ALLOC:
 	case PTR_TO_BTF_ID | PTR_TRUSTED:
 	case PTR_TO_BTF_ID | MEM_RCU:
-	case PTR_TO_BTF_ID | MEM_ALLOC | PTR_TRUSTED:
 	case PTR_TO_BTF_ID | MEM_ALLOC | NON_OWN_REF:
 		/* When referenced PTR_TO_BTF_ID is passed to release function,
 		 * its fixed offset must be 0. In the other cases, fixed offset
@@ -9211,7 +9210,6 @@ static int check_reg_allocation_locked(struct bpf_verifier_env *env, struct bpf_
 		ptr = reg->map_ptr;
 		break;
 	case PTR_TO_BTF_ID | MEM_ALLOC:
-	case PTR_TO_BTF_ID | MEM_ALLOC | PTR_TRUSTED:
 		ptr = reg->btf;
 		break;
 	default: