Use uwsgi binary from path

All these uwsgi invocations assume that the uwsgi binary is in the
same directory as their project binaries are installed into (probably
/usr/bin).  That may not be correct -- for example if using a packaged
uwsgi on Fedora the binary will live in /usr/sbin/uwsgi (not /usr/bin
where the project files from pip are).

Switch invocations to just find it in the path.

Change-Id: I298e3374e9c84e209ffcabbaaacda17f8df19f4f
diff --git a/lib/nova b/lib/nova
index a842a61..c7ffe7f 100644
--- a/lib/nova
+++ b/lib/nova
@@ -864,7 +864,7 @@
             start_tls_proxy nova '*' $NOVA_SERVICE_PORT $NOVA_SERVICE_HOST $NOVA_SERVICE_PORT_INT
         fi
     else
-        run_process "n-api" "$NOVA_BIN_DIR/uwsgi --procname-prefix nova-api --ini $NOVA_UWSGI_CONF"
+        run_process "n-api" "$(which uwsgi) --procname-prefix nova-api --ini $NOVA_UWSGI_CONF"
         nova_url=$service_protocol://$SERVICE_HOST/compute/v2.1/
     fi
 
@@ -955,7 +955,7 @@
     if [ "$NOVA_USE_MOD_WSGI" == "False" ]; then
         run_process n-api-meta "$NOVA_BIN_DIR/nova-api-metadata --config-file $compute_cell_conf"
     else
-        run_process n-api-meta "$NOVA_BIN_DIR/uwsgi --procname-prefix nova-api-meta --ini $NOVA_METADATA_UWSGI_CONF"
+        run_process n-api-meta "$(which uwsgi) --procname-prefix nova-api-meta --ini $NOVA_METADATA_UWSGI_CONF"
     fi
 
     export PATH=$old_path