Minor cleanups in py-inferior.exp

While working on this series, I noticed a some oddities in
py-inferior.exp.  One is an obviously incorrect comment, and the
others are confusing test names.  This patch fixes these.

Approved-By: Pedro Alves <pedro@palves.net>
diff --git a/gdb/testsuite/gdb.python/py-inferior.exp b/gdb/testsuite/gdb.python/py-inferior.exp
index 58deece..576c2b7 100644
--- a/gdb/testsuite/gdb.python/py-inferior.exp
+++ b/gdb/testsuite/gdb.python/py-inferior.exp
@@ -206,8 +206,7 @@
     }
 }
 
-# Test Inferior is_valid.  This must always be the last test in
-# this testcase as it kills the inferior.
+# Test Inferior is_valid.
 
 with_test_prefix "is_valid" {
     gdb_py_test_silent_cmd "python inf_list = gdb.inferiors()" "get initial list" 1
@@ -247,7 +246,7 @@
     gdb_test "python print (inf_list\[1\].is_valid())" "True" \
 	"check inferior validity 3"
 
-    gdb_test_no_output "remove-inferiors 2" "remove-inferiors 3"
+    gdb_test_no_output "remove-inferiors 2"
     gdb_test "python print (inf_list\[0\].is_valid())" "True" \
 	"check inferior validity 4"
 
@@ -318,7 +317,7 @@
 	"print a connection object"
 
     gdb_test "inferior 1" ".*" "switch back to first inferior"
-    gdb_test_no_output "remove-inferiors 3" "remove second inferior"
+    gdb_test_no_output "remove-inferiors 3"
 }
 
 # Test repr()/str()