Correct spelling mistakes.

code/client/snd_dma.c

@@ -432,7 +432,7 @@ void S_SpatializeOrigin (vec3_t origin, int master_vol, int *left_vol, int *righ
 
 	const float dist_mult = SOUND_ATTENUATE;
 	
-	// calculate stereo seperation and distance attenuation
+	// calculate stereo separation and distance attenuation
 	VectorSubtract(origin, listener_origin, source_vec);
 
 	dist = VectorNormalize(source_vec);