Fix tests to reflect new filesize.

tests/acceptance/environment.rb

@@ -7,6 +7,8 @@ class Environment
 
   def initialize
     # Make sure we have a few pages of memory so we can test msync offsets
+    # NB If you change this, you need to match it in the flexnbd/fake_dest
+    # Flexnbd::FakeDest::Client#write_hello
     @blocksize = Integer(`getconf PAGE_SIZE`) * 4
     @filename1 = "/tmp/.flexnbd.test.#{$PROCESS_ID}.#{Time.now.to_i}.1"
     @filename2 = "/tmp/.flexnbd.test.#{$PROCESS_ID}.#{Time.now.to_i}.2"

tests/acceptance/flexnbd/fake_dest.rb

@@ -22,7 +22,7 @@ module FlexNBD
         if opts[:size] == :wrong
           write_rand(@sock, 8)
         else
-          @sock.write("\x00\x00\x00\x00\x00\x00\x10\x00")
+          @sock.write("\x00\x00\x00\x00\x00\x01\x00\x00")
         end
 
         @sock.write("\x00" * 128)