vmxcap: Open MSR file in unbuffered mode

Python may otherwise decide to to read larger chunks, applying the seek
only on the software buffer. This will return results from the wrong
MSRs.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>

scripts/kvm/vmxcap

@@ -27,9 +27,9 @@ MSR_IA32_VMX_VMFUNC = 0x491
 class msr(object):
     def __init__(self):
         try:
-            self.f = file('/dev/cpu/0/msr')
+            self.f = open('/dev/cpu/0/msr', 'r', 0)
         except:
-            self.f = file('/dev/msr0')
+            self.f = open('/dev/msr0', 'r', 0)
     def read(self, index, default = None):
         import struct
         self.f.seek(index)