Fix python exec prefix on SUSE.

https://bugs.launchpad.net/devstack/+bug/1068386
"sudo python setup.py develop" installs to /usr/bin on SUSE

Otherwise it fails with "stack.sh:191 g-api did not start".

Change-Id: I1258240ce2a5a765188353fbc8a2e085d0b02fec
diff --git a/functions b/functions
index c611e00..70ab999 100644
--- a/functions
+++ b/functions
@@ -1410,7 +1410,7 @@
 # Get the path to the direcotry where python executables are installed.
 # get_python_exec_prefix
 function get_python_exec_prefix() {
-    if is_fedora; then
+    if is_fedora || is_suse; then
         echo "/usr/bin"
     else
         echo "/usr/local/bin"