libc: fix fstatfs() implementation.

The syscall expects the size of the buffer as the second argument.

Change-Id: I99ede2fec7fcd385ca03ff022c2cffa4297bea8d
diff --git a/libc/arch-x86/syscalls.mk b/libc/arch-x86/syscalls.mk
index bd9a9ab..6ac3716 100644
--- a/libc/arch-x86/syscalls.mk
+++ b/libc/arch-x86/syscalls.mk
@@ -77,7 +77,7 @@
 syscall_src += arch-x86/syscalls/fchown.S
 syscall_src += arch-x86/syscalls/sync.S
 syscall_src += arch-x86/syscalls/__fcntl64.S
-syscall_src += arch-x86/syscalls/fstatfs.S
+syscall_src += arch-x86/syscalls/__fstatfs64.S
 syscall_src += arch-x86/syscalls/sendfile.S
 syscall_src += arch-x86/syscalls/fstatat.S
 syscall_src += arch-x86/syscalls/mkdirat.S