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/fstatfs.S b/libc/arch-arm/syscalls/__fstatfs64.S
similarity index 81%
rename from libc/arch-arm/syscalls/fstatfs.S
rename to libc/arch-arm/syscalls/__fstatfs64.S
index 88150d6..00b4e41 100644
--- a/libc/arch-arm/syscalls/fstatfs.S
+++ b/libc/arch-arm/syscalls/__fstatfs64.S
@@ -2,12 +2,12 @@
 #include <sys/linux-syscalls.h>
 
     .text
-    .type fstatfs, #function
-    .globl fstatfs
+    .type __fstatfs64, #function
+    .globl __fstatfs64
     .align 4
     .fnstart
 
-fstatfs:
+__fstatfs64:
     .save   {r4, r7}
     stmfd   sp!, {r4, r7}
     ldr     r7, =__NR_fstatfs64