Fix meson AVX2 fixed-point

Author: jmvalin

silk/meson.build

@@ -44,9 +44,7 @@ foreach intr_name : ['sse4_1', 'avx2', 'neon_intr']
   endif
 
   intr_sources = get_variable('silk_sources_' + intr_name)
-  if opt_fixed_point
-    intr_sources += get_variable('silk_sources_fixed_' + intr_name)
-  else
+  if not opt_fixed_point
     intr_sources += get_variable('silk_sources_float_' + intr_name)
   endif