fix (hopefully) statvfs breakage on x86_64 that resulted from fixing i386...

src/stat/fstatvfs.c

@@ -4,7 +4,11 @@
 
 int fstatvfs(int fd, struct statvfs *buf)
 {
-	return syscall(SYS_fstatfs, fd, sizeof *buf, buf);
+#ifdef SYS_fstatfs64
+	return syscall(SYS_fstatfs64, fd, sizeof *buf, buf);
+#else
+	return syscall(SYS_fstatfs, fd, buf);
+#endif
 }
 
 weak_alias(fstatvfs, fstatfs);

src/stat/statvfs.c

@@ -4,7 +4,11 @@
 
 int statvfs(const char *path, struct statvfs *buf)
 {
-	return syscall(SYS_statfs, path, sizeof *buf, buf);
+#ifdef SYS_statfs64
+	return syscall(SYS_statfs64, path, sizeof *buf, buf);
+#else
+	return syscall(SYS_statfs, path, buf);
+#endif
 }
 
 weak_alias(statvfs, statfs);