PHAL: disable attributes tool debug traces

Attributes "import" options prints debug data in the console.
currently tool is not providing no option to disable this.
This commits stop printing data into journals to log unwanted
data in journal.

Tested: verified using command line option

Signed-off-by: Jayanth Othayoth <ojayanth@in.ibm.com>
Change-Id: Ia21ddeee9b13f0f999bfac88b5985999be762d2c
diff --git a/procedures/phal/import_devtree.cpp b/procedures/phal/import_devtree.cpp
index 1a18bbe..6d8adc4 100644
--- a/procedures/phal/import_devtree.cpp
+++ b/procedures/phal/import_devtree.cpp
@@ -47,6 +47,8 @@
         std::string cmd("/usr/bin/attributes ");
         cmd += "import ";
         cmd += DEVTREE_EXP_FILE;
+        cmd += " 2>";
+        cmd += " /dev/null";
         execl("/bin/sh", "sh", "-c", cmd.c_str(), 0);
 
         auto error = errno;