Fix some typos in log and test

Change from "seperate" to "separate".
Change from "priviledge" to "privilege".

Change-Id: I541881d9ab0261de303a5759f80c72f0352261cd
diff --git a/tempest/api/network/test_security_groups.py b/tempest/api/network/test_security_groups.py
index 3d26b48..f9af3cc 100644
--- a/tempest/api/network/test_security_groups.py
+++ b/tempest/api/network/test_security_groups.py
@@ -162,7 +162,7 @@
         """Verify security group rule for icmp protocol works.
 
         Specify icmp type (port_range_min) and icmp code
-        (port_range_max) with different values. A seperate testcase
+        (port_range_max) with different values. A separate testcase
         is added for icmp protocol as icmp validation would be
         different from tcp/udp.
         """