pull: convert get_tracking_branch to use refspec_item_init

Convert 'get_tracking_branch()' to use 'refspec_item_init()' instead of
the old 'parse_fetch_refspec()' function.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/pull.c

@@ -676,12 +676,12 @@ static const char *get_upstream_branch(const char *remote)
  */
 static const char *get_tracking_branch(const char *remote, const char *refspec)
 {
-	struct refspec_item *spec;
+	struct refspec_item spec;
 	const char *spec_src;
 	const char *merge_branch;
 
-	spec = parse_fetch_refspec(1, &refspec);
-	spec_src = spec->src;
+	refspec_item_init(&spec, refspec, REFSPEC_FETCH);
+	spec_src = spec.src;
 	if (!*spec_src || !strcmp(spec_src, "HEAD"))
 		spec_src = "HEAD";
 	else if (skip_prefix(spec_src, "heads/", &spec_src))
@@ -701,7 +701,7 @@ static const char *get_tracking_branch(const char *remote, const char *refspec)
 	} else
 		merge_branch = NULL;
 
-	free_refspec(1, spec);
+	refspec_item_clear(&spec);
 	return merge_branch;
 }