merge from open-source master

Change-Id: Iecfd2bd3069f70bbe508042cc249fcf7ff24800d

libc/stdio/flockfile.c

@@ -205,8 +205,6 @@ __fremovelock(FILE*  fp)
             lock->file = NULL;
         }
         lock_table_unlock(t);
-
-        if (lock != NULL)
-            free(lock);
+        free(lock);
     }
 }

libc/string/strndup.c

@@ -31,12 +31,14 @@
 char*  strndup(const char*  s, size_t n)
 {
     size_t  slen = (size_t)strlen(s);
-    int     len  = slen < n ? slen : n;
-    char*   copy = malloc(len+1);
+    char*   copy;
 
+    if (slen < n)
+        n = slen;
+    copy = malloc(n+1);
     if (copy) {
-        memcpy( copy, s, len );
-        copy[len] = 0;
+        memcpy(copy, s, n);
+        copy[n] = 0;
     }
     return copy;
 }