Add O_PATH support for flistxattr()

A continuation of commit 2825f10b7f61558c264231a536cf3affc0d84204.

Add O_PATH compatibility support for flistxattr(). This allows
a process to list out all the extended attributes associated with
O_PATH file descriptors.

Change-Id: Ie2285ac7ad2e4eac427ddba6c2d182d41b130f75
diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index 4890b89..23cc3b6 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -124,7 +124,7 @@
 void        sync(void)  all
 int         ___fsetxattr:fsetxattr(int, const char*, const void*, size_t, int) all
 ssize_t     ___fgetxattr:fgetxattr(int, const char*, void*, size_t) all
-ssize_t     flistxattr(int, char*, size_t) all
+ssize_t     ___flistxattr:flistxattr(int, char*, size_t) all
 int         fremovexattr(int, const char*) all
 
 int __getdents64:getdents64(unsigned int, struct dirent*, unsigned int)   arm,arm64,mips,mips64,x86,x86_64