Fix a leak in print_status(), the compute_rev_name() function
implemented in this file will return a strbuf_detach()'d value, or
NULL.

This leak has existed since this code was added in
a9f8a37584a (submodule: port submodule subcommand 'status' from shell
to C, 2017-10-06), but in 0b5e2ea7cf3 (submodule--helper: don't print
null in 'submodule status', 2018-04-18) we added a "const"
intermediate variable for the return value, that "const" should be
removed.

Signed-off-by: Ævar Arnfjörð Bjarmason <redacted>
---
 builtin/submodule--helper.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 642595cc3f4..75e842af5ca 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c

@@ -643,10 +643,11 @@ static void print_status(unsigned int flags, char state, const char *path,
 	printf("%c%s %s", state, oid_to_hex(oid), displaypath);
 
 	if (state == ' ' || state == '+') {
-		const char *name = compute_rev_name(path, oid_to_hex(oid));
+		char *name = compute_rev_name(path, oid_to_hex(oid));
 
 		if (name)
 			printf(" (%s)", name);
+		free(name);
 	}
 
 	printf("\n");

-- 
2.37.1.1062.g385eac7fccf