obs-filters: Fix macro check

This should be checking true or false -- not whether it's defined or
not.

plugins/obs-filters/obs-filters.c

@@ -15,7 +15,7 @@ extern struct obs_source_info color_key_filter;
 extern struct obs_source_info sharpness_filter;
 extern struct obs_source_info chroma_key_filter;
 extern struct obs_source_info async_delay_filter;
-#ifdef SPEEXDSP_ENABLED
+#if SPEEXDSP_ENABLED
 extern struct obs_source_info noise_suppress_filter;
 #endif
 extern struct obs_source_info noise_gate_filter;
@@ -32,7 +32,7 @@ bool obs_module_load(void)
 	obs_register_source(&sharpness_filter);
 	obs_register_source(&chroma_key_filter);
 	obs_register_source(&async_delay_filter);
-#ifdef SPEEXDSP_ENABLED
+#if SPEEXDSP_ENABLED
 	obs_register_source(&noise_suppress_filter);
 #endif
 	obs_register_source(&noise_gate_filter);