Fix PNOR command check execution

The pflash command is suppose to be executed on BMC and not on OS.

Change-Id: I93404bb6c2e7117891afd6470f01bc34499ff45e
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/lib/utils.robot b/lib/utils.robot
index 133654e..b333aea 100755
--- a/lib/utils.robot
+++ b/lib/utils.robot
@@ -81,7 +81,7 @@
     # FFS: Flash header not found. Code: 100
     # Error 100 opening ffs !
 
-    ${pnor_info}=  OS Execute Command  ${pflash_cmd}
+    ${pnor_info}=  BMC Execute Command  ${pflash_cmd}
     Should Not Contain Any  ${pnor_info}  Flash header not found  Error