Resolver: fixed allocation error handling while resolving SRV.

src/core/ngx_resolver.c

diff --git a/src/core/ngx_resolver.c b/src/core/ngx_resolver.c
index e140ab6..a18fd1f 100644
--- a/src/core/ngx_resolver.c
+++ b/src/core/ngx_resolver.c
@@ -443,7 +443,7 @@
 
         name.data = ngx_resolver_alloc(r, name.len);
         if (name.data == NULL) {
-            return NGX_ERROR;
+            goto failed;
         }
 
         if (slen == ctx->service.len) {
@@ -481,6 +481,8 @@
         ngx_resolver_free(r, ctx->event);
     }
 
+failed:
+
     ngx_resolver_free(r, ctx);
 
     return NGX_ERROR;