yadif: Fix compiler warning caused by specifying const twice

  yadif.c:49:24: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier]
  DECLARE_ASM_CONST (16, const xmm_reg, pb_1) = {
                       ^
  yadif.c:33:50: note: expanded from macro 'DECLARE_ASM_CONST'
  #define DECLARE_ASM_CONST(n,t,v)    static const t __attribute__((used)) __attribute__ ((aligned (n))) v
                                                 ^
  yadif.c:52:24: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier]
  DECLARE_ASM_CONST (16, const xmm_reg, pw_1) = {
                       ^
  yadif.c:33:50: note: expanded from macro 'DECLARE_ASM_CONST'
  #define DECLARE_ASM_CONST(n,t,v)    static const t __attribute__((used)) __attribute__ ((aligned (n)))
diff --git a/gst/yadif/yadif.c b/gst/yadif/yadif.c
index 2c92999..4bbf6c5 100644
--- a/gst/yadif/yadif.c
+++ b/gst/yadif/yadif.c
@@ -46,10 +46,10 @@
 
 #define MANGLE(a) EXTERN_PREFIX LOCAL_MANGLE(a)
 
-DECLARE_ASM_CONST (16, const xmm_reg, pb_1) = {
+DECLARE_ASM_CONST (16, xmm_reg, pb_1) = {
 0x0101010101010101ULL, 0x0101010101010101ULL};
 
-DECLARE_ASM_CONST (16, const xmm_reg, pw_1) = {
+DECLARE_ASM_CONST (16, xmm_reg, pw_1) = {
 0x0001000100010001ULL, 0x0001000100010001ULL};