Fix cdrom detection

waagent is trying to detect if there's a virtual cdrom by grepping
fdisk output, except that the output is different if we're not using
en locale. Use LC_ALL=C to make sure we'll have "correct" output

Signed-off-by: Arnaud Patard <apatard@hupstream.com>

waagent

@@ -1843,7 +1843,7 @@ class Agent(Util):
         if os.path.exists("/dev/sr0"):
             dvd = "/dev/sr0"
         modloaded=False
-        if Run("fdisk -l " + dvd + " | grep Disk",chk_err=False):
+        if Run("LC_ALL=C fdisk -l " + dvd + " | grep Disk",chk_err=False):
             # Is it possible to load a module for ata_piix?
             retcode,krn=RunGetOutput('uname -r')
             if retcode: