libyang REFACTOR avoid connection between context and log location storage

libyang works strictly with a single context now, so it is not necessary
to connect the log location information with a specific context. It also
clarifies what to do when the context is not available in the function
but still a location information in an error message could be useful.
diff --git a/src/parser_stmt.c b/src/parser_stmt.c
index c36cbf6..12748a8 100644
--- a/src/parser_stmt.c
+++ b/src/parser_stmt.c
@@ -846,7 +846,7 @@
     pctx.format = LYS_IN_YANG;
     pctx.parsed_mod = ctx->pmod;
 
-    LOG_LOCSET(ctx->ctx, NULL, NULL, ctx->path, NULL);
+    LOG_LOCSET(NULL, NULL, ctx->path, NULL);
 
     switch (kw) {
     case LY_STMT_STATUS:
@@ -865,6 +865,6 @@
         return LY_EINT;
     }
 
-    LOG_LOCBACK(ctx->ctx, 0, 0, 1, 0);
+    LOG_LOCBACK(0, 0, 1, 0);
     return ret;
 }