A previous cleanup commit inverted a statement that checked the return value of
a KMSDRM_CreateSurfaces call during KMSDRM_CreateWindow, which causes the video
backend to always fail despite success.
This commit restores the intended behavior.
Fixes: 3c501b963d ("Clang-Tidy fixes (#6725)").
Simple DirectMedia Layer is a cross-platform development library designed
to provide low level access to audio, keyboard, mouse, joystick, and graphics
hardware via OpenGL and Direct3D. It is used by video playback software,
emulators, and popular games including Valve's award winning catalog
and many Humble Bundle games.
More extensive documentation is available in the docs directory, starting
with README.md