compositor-rdp: free() can handle NULL pointers
compositor-rdp: free() can handle NULL pointers

There's no need to check if a pointer exists before passing it to free().
free() can handle NULL pointers.

Signed-off-by: Dawid Gajownik <158b9a61e3d4d82c23fe617ac4e66be51690b385@gmail.com>
Reviewed-By: David FORT <1a73af9e7ae00182733b2292511b814be66f065f@hardening-consulting.com>

Tarnyko/weston-xdg_surface_present,xorgy/weston,Fantu/compositor-spice,giucam/weston,giucam/weston,udoprog/weston,kwm81/weston,jonnylamb/weston,sir-murray/weston,Tarnyko/weston-xdg_surface_present,sir-murray/weston,Gnurou/weston,krezovic/weston,Fantu/compositor-spice,xorgy/weston,kwm81/weston,krezovic/weston,Fantu/compositor-spice,udoprog/weston,Gnurou/weston,jonnylamb/weston