libc: fix fstatfs() implementation.

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

Change-Id: I99ede2fec7fcd385ca03ff022c2cffa4297bea8d
diff --git a/libc/arch-arm/syscalls.mk b/libc/arch-arm/syscalls.mk
index f6312e5..8afe099 100644
--- a/libc/arch-arm/syscalls.mk
+++ b/libc/arch-arm/syscalls.mk
@@ -74,7 +74,7 @@
 syscall_src += arch-arm/syscalls/fchown.S
 syscall_src += arch-arm/syscalls/sync.S
 syscall_src += arch-arm/syscalls/__fcntl64.S
-syscall_src += arch-arm/syscalls/fstatfs.S
+syscall_src += arch-arm/syscalls/__fstatfs64.S
 syscall_src += arch-arm/syscalls/sendfile.S
 syscall_src += arch-arm/syscalls/fstatat.S
 syscall_src += arch-arm/syscalls/mkdirat.S