libbpf: Rename RELO_EXTERN to RELO_EXTERN_VAR

mainline inclusion
from mainline-5.13-rc1
commit 0c091e5c
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0c091e5c2d37696589a3e0131a809b5499899995

-------------------------------------------------

This patch renames RELO_EXTERN to RELO_EXTERN_VAR.
It is to avoid the confusion with a later patch adding
RELO_EXTERN_FUNC.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015221.1547722-1-kafai@fb.com
(cherry picked from commit 0c091e5c)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

tools/lib/bpf/libbpf.c

@@ -185,7 +185,7 @@ enum reloc_type {
 	RELO_LD64,
 	RELO_CALL,
 	RELO_DATA,
-	RELO_EXTERN,
+	RELO_EXTERN_VAR,
 	RELO_SUBPROG_ADDR,
 };
 
@@ -3456,7 +3456,7 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
 		}
 		pr_debug("prog '%s': found extern #%d '%s' (sym %d) for insn #%u\n",
 			 prog->name, i, ext->name, ext->sym_idx, insn_idx);
-		reloc_desc->type = RELO_EXTERN;
+		reloc_desc->type = RELO_EXTERN_VAR;
 		reloc_desc->insn_idx = insn_idx;
 		reloc_desc->sym_off = i; /* sym_off stores extern index */
 		return 0;
@@ -6272,7 +6272,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
 			insn[0].imm = obj->maps[relo->map_idx].fd;
 			relo->processed = true;
 			break;
-		case RELO_EXTERN:
+		case RELO_EXTERN_VAR:
 			ext = &obj->externs[relo->sym_off];
 			if (ext->type == EXT_KCFG) {
 				insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;