Clean up compile_ovn function's parameters

That function was accepting 3 positional arguments and first
of them was boolean value "build_modules" which isn't used anywhere in
that function.
So this patch cleans it a bit by removing that not used parameter.

Change-Id: I5c57b9116338a63b7bfb170c02e33bb4eae725da
diff --git a/lib/neutron_plugins/ovn_agent b/lib/neutron_plugins/ovn_agent
index 3fc3828..099b639 100644
--- a/lib/neutron_plugins/ovn_agent
+++ b/lib/neutron_plugins/ovn_agent
@@ -294,16 +294,13 @@
 
 # compile_ovn() - Compile OVN from source and load needed modules
 #                 Accepts three parameters:
-#                   - first optional is False by default and means that
-#                     modules are built and installed.
-#                   - second optional parameter defines prefix for
+#                   - first optional parameter defines prefix for
 #                     ovn compilation
-#                   - third optional parameter defines localstatedir for
+#                   - second optional parameter defines localstatedir for
 #                     ovn single machine runtime
 function compile_ovn {
-    local build_modules=${1:-False}
-    local prefix=$2
-    local localstatedir=$3
+    local prefix=$1
+    local localstatedir=$2
 
     if [ -n "$prefix" ]; then
         prefix="--prefix=$prefix"
@@ -381,7 +378,7 @@
 
         compile_ovs $OVN_BUILD_MODULES
         if use_new_ovn_repository; then
-            compile_ovn $OVN_BUILD_MODULES
+            compile_ovn
         fi
 
         sudo mkdir -p $OVS_PREFIX/var/log/openvswitch