remove incorrect (void)

n_coeffs is used in this function

Change-Id: I5f5d2933304bb636a33e0fa294b4526edb65a08d
diff --git a/vpx_dsp/arm/highbd_quantize_neon.c b/vpx_dsp/arm/highbd_quantize_neon.c
index 0a0ab5e..c2ad34a 100644
--- a/vpx_dsp/arm/highbd_quantize_neon.c
+++ b/vpx_dsp/arm/highbd_quantize_neon.c
@@ -176,9 +176,6 @@
     vst1_lane_u16(eob_ptr, eob_max_2, 0);
   }
 #endif  // VPX_ARCH_AARCH64
-  // Need these here, else the compiler complains about mixing declarations and
-  // code in C90
-  (void)n_coeffs;
 }
 
 static VPX_FORCE_INLINE int32x4_t extract_sign_bit(int32x4_t a) {