Free memory returned by xf86GetEntityInfo

We were leaking it.

(Ported from amdgpu commit cfccf4c4e7e5c73fe4040fabeb1b43283cf29b33)
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

src/radeon_kms.c

@@ -228,6 +228,7 @@ static void RADEONFreeRec(ScrnInfoPtr pScrn)
 	info->accel_state = NULL;
     }
 
+    free(info->pEnt);
     free(pScrn->driverPrivate);
     pScrn->driverPrivate = NULL;
 }