Fix HTX Tool exist failure

Keyword "HTX Tool Exist" is deprecated and need use the new generic
keyword "Tool Exist".

Change-Id: I8a97444c860a07696bf26a25ba574e89f47c18e1
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/syslib/utils_os.robot b/syslib/utils_os.robot
index ae27a3a..9e7d36b 100755
--- a/syslib/utils_os.robot
+++ b/syslib/utils_os.robot
@@ -215,7 +215,7 @@
     # 2. Power on
 
     Boot To OS
-    HTX Tool Exist
+    Tool Exist  htxcmdline
 
     # Shutdown if HTX is running.
     ${status}=  Run Keyword And Return Status  Is HTX Running