make niri-session POSIX compatible (#970)

* make niri-session POSIX compatible

* Update resources/niri-session

---------

Co-authored-by: Ivan Molodetskikh <yalterz@gmail.com>

resources/niri-session

@@ -12,7 +12,7 @@ if [ -n "$SHELL" ] &&
 fi
 
 # Try to detect the service manager that is being used
-if hash systemctl &> /dev/null; then
+if hash systemctl >/dev/null 2>&1; then
     # Make sure there's no already running session.
     if systemctl --user -q is-active niri.service; then
       echo 'A niri session is already running.'
@@ -41,15 +41,15 @@ if hash systemctl &> /dev/null; then
 
     # Unset environment that we've set.
     systemctl --user unset-environment WAYLAND_DISPLAY XDG_SESSION_TYPE XDG_CURRENT_DESKTOP NIRI_SOCKET
-elif hash dinitctl &> /dev/null; then
+elif hash dinitctl >/dev/null 2>&1; then
     # Check that the user dinit daemon is running
-    if ! pgrep -u $(id -u) dinit &> /dev/null; then
+    if ! pgrep -u "$(id -u)" dinit >/dev/null 2>&1; then
       echo "dinit user daemon is not running."
       exit 1
     fi
 
     # Make sure there's no already running session.
-    if dinitctl --user is-started niri &> /dev/null; then
+    if dinitctl --user is-started niri >/dev/null 2>&1; then
       echo 'A niri session is already running.'
       exit 1
     fi