fix gcc warnings about uninitialized variables

like:

src/shared/install.c: In function ‘unit_file_lookup_state’:
src/shared/install.c:1861:16: warning: ‘r’ may be used uninitialized in
this function [-Wmaybe-uninitialized]
         return r < 0 ? r : state;
                ^
src/shared/install.c:1796:13: note: ‘r’ was declared here
         int r;
             ^

1 files changed, 1 insertions, 1 deletions

diff --git a/src/resolve/test-dns-domain.c b/src/resolve/test-dns-domain.c
index 2f3edaf783..c3208abc78 100644
--- a/src/resolve/test-dns-domain.c
+++ b/src/resolve/test-dns-domain.c
@@ -161,7 +161,7 @@ static void test_dns_name_single_label(void) {
 
 static void test_dns_name_reverse_one(const char *address, const char *name) {
         _cleanup_free_ char *p = NULL;
-        union in_addr_union a, b;
+        union in_addr_union a, b = {};
         int familya, familyb;
 
         assert_se(in_addr_from_string_auto(address, &familya, &a) >= 0);