Fix cosmetic error when "lsmod | grep ata_piix" fails to find the ata_piix.ko module

Changed:
TryLoadAtapiix() added chk_err=False to prevent error output if lsmod | grep ata_piix fails.

waagent

@@ -1828,7 +1828,7 @@ class Agent(Util):
         modloaded=False
         retcode,krn=RunGetOutput('uname -r')
         krn_pth='/lib/modules/'+krn.strip('\n')+'/kernel/drivers/ata/ata_piix.ko'
-        if Run('lsmod | grep ata_piix') == 0 :
+        if Run("lsmod | grep ata_piix",chk_err=False) == 0 :
             Log("Module " + krn_pth + " driver for ATAPI CD-ROM is already present.")
             return 0
         if retcode:
@@ -1845,7 +1845,7 @@ class Agent(Util):
         time.sleep(1)
         # check 3 times if the mod is loaded
         for i in range(3):
-            if Run('lsmod | grep ata_piix'):
+            if Run("lsmod | grep ata_piix", chk_err=False):
                 continue
             else :
                 modloaded=True