refactor: do some internal refactor.

include/util/tlog.h

@@ -89,7 +89,7 @@ bool taosAssertRelease(bool condition);
 // Disable all asserts that may compromise the performance.
 #if defined DISABLE_ASSERT
 #define ASSERT(condition)
-#define ASSERTS(condition, ...)
+#define ASSERTS(condition, ...)    (0)
 #else
 #define ASSERTS(condition, ...) taosAssertDebug(condition, __FILE__, __LINE__, __VA_ARGS__)
 #ifdef NDEBUG

source/util/src/tutil.c

@@ -159,10 +159,6 @@ char *strtolower(char *dst, const char *src) {
   int32_t esc = 0;
   char    quote = 0, *p = dst, c;
 
-  if (ASSERTS(dst != NULL, "dst is NULL")) {
-    return NULL;
-  }
-
   for (c = *src++; c; c = *src++) {
     if (esc) {
       esc = 0;
@@ -188,10 +184,6 @@ char *strntolower(char *dst, const char *src, int32_t n) {
   int32_t esc = 0;
   char    quote = 0, *p = dst, c;
 
-  if (ASSERTS(dst != NULL, "dst is NULL")) {
-    return NULL;
-  }
-  
   if (n == 0) {
     *p = 0;
     return dst;
@@ -219,11 +211,6 @@ char *strntolower(char *dst, const char *src, int32_t n) {
 
 char *strntolower_s(char *dst, const char *src, int32_t n) {
   char *p = dst, c;
-
-  if (ASSERTS(dst != NULL, "dst is NULL")) {
-    return NULL;
-  }
-
   if (n == 0) {
     return NULL;
   }