fix: log error but not crash if found an imcomplete replica path (#1428)

#1383

The replica instance path will be removed to trash path, a.k.a
`<table_id>.<pid>.<timestamp>.err`, but it may not complete when
a replica server crash, then the path is left but some files
(e.g. `.init-info`) in the path have been moved. When restart
the server after that, server will crash because of a check on
existence of the files, which is not necessary, the server is
able to trash the corrupt path and start normally, the missing
replica can be recovered from other servers automatically.

This patch removes the check.

src/replica/replication_app_base.cpp

@@ -117,7 +117,10 @@ error_code write_blob_to_file(const std::string &file, const blob &data)
 error_code replica_init_info::load(const std::string &dir)
 {
     std::string info_path = utils::filesystem::path_combine(dir, kInitInfo);
-    CHECK(utils::filesystem::path_exists(info_path), "file({}) not exist", info_path);
+    ERR_LOG_AND_RETURN_NOT_TRUE(utils::filesystem::path_exists(info_path),
+                                ERR_PATH_NOT_FOUND,
+                                "file({}) not exist",
+                                info_path);
     ERR_LOG_AND_RETURN_NOT_OK(
         load_json(info_path), "load replica_init_info from {} failed", info_path);
     LOG_INFO("load replica_init_info from {} succeed: {}", info_path, to_string());

src/replica/replication_app_base.h

@@ -39,6 +39,7 @@
 #include "replica/replica_base.h"
 #include "replica_admin_types.h"
 #include "utils/error_code.h"
+#include "utils/ports.h"
 
 namespace dsn {
 class app_info;
@@ -69,7 +70,7 @@ class replica_init_info
 
 public:
     replica_init_info() { memset((void *)this, 0, sizeof(*this)); }
-    error_code load(const std::string &dir);
+    error_code load(const std::string &dir) WARN_UNUSED_RESULT;
     error_code store(const std::string &dir);
     std::string to_string();