make the code to look safe, not only be safe

ndb/src/common/util/strdup.c

@@ -21,7 +21,7 @@
 char *
 strdup(const char *s){
   void *p2;
-  p2 = malloc(strlen(s)+1);
+  if ((p2 = malloc(strlen(s)+1)))
     strcpy(p2, s);
   return p2;
 }

sql/log.cc

@@ -2247,9 +2247,9 @@ void print_buffer_to_nt_eventlog(enum loglevel level, char *buff,
   DBUG_ENTER("print_buffer_to_nt_eventlog");
 
   buffptr= buff;
-  if (length > (uint)(buffLen-4))
+  if (length > (uint)(buffLen-5))
   {
-    char *newBuff= new char[length + 4];
+    char *newBuff= new char[length + 5];
     strcpy(newBuff, buff);
     buffptr= newBuff;
   }