Keyword "Check HTX Run Status" is failing

Fix typo, sleep-time should be sleep_time.
Return From Keyword should be a string test because sleep_time
input parameter is specified as a character string such as "20m".

Resolves openbmc/openbmc-test-automation#1419

Change-Id: I264163abd998a96e4bbf54f3717823c8a84c1c11
Signed-off-by: Steven Sombar <ssombar@us.ibm.com>
diff --git a/syslib/utils_os.robot b/syslib/utils_os.robot
index d9c0387..b5ff68b 100755
--- a/syslib/utils_os.robot
+++ b/syslib/utils_os.robot
@@ -499,7 +499,8 @@
     [Arguments]  ${sleep_time}=${0}
 
     # Description of argument(s):
-    # sleep_time  The amount of time to sleep after checking status.
+    # sleep_time  The amount of time to sleep after checking status,
+    #             for example "3s" or "2m".
 
     Rprint Timen  Check HTX mdt Status and error.
     ${htx_status}  ${stderr}  ${rc}=  OS Execute Command
@@ -513,9 +514,9 @@
     Should Contain  ${htx_errlog}  file </tmp/htxerr> is empty
     ...  msg=HTX geterrorlog was not empty.
 
-    Return From Keyword If  ${sleep_time} == ${0}
+    Return From Keyword If  "${sleep_time}" == "${0}"
 
-    Run Key U  Sleep \ ${sleep-time}
+    Run Key U  Sleep \ ${sleep_time}
 
 
 Shutdown HTX Exerciser
@@ -670,4 +671,4 @@
     [Documentation]  Stop the bootme process.
 
     ${output}  ${stderr}  ${rc}=  OS Execute Command  htxcmdline -bootme off
-    Should Contain  ${output}  bootme off is completed successfully
\ No newline at end of file
+    Should Contain  ${output}  bootme off is completed successfully