clang++ fix.

"C++11 requires lambda with omitted result type to consist of a single return statement"

clang++ fix.
ba237fbd · Silas Boyd-Wickizer · d897d91b · ba237fbd
--- a/sysfile.cc
+++ b/sysfile.cc
@@ -183,7 +183,7 @@ isdirempty(struct inode *dp)
 {
  dir_init(dp);
  int empty = 1;
-  dp->dir->enumerate([&empty](const strbuf<DIRSIZ> &name, u64 ino) {
+  dp->dir->enumerate([&empty](const strbuf<DIRSIZ> &name, u64 ino)->bool{
      if (!strcmp(name._buf, "."))
        return false;
      if (!strcmp(name._buf, ".."))