g723.1: simplify scale_vector()

It is impossible for bits to be 15 here so the special case is
not needed.
Signed-off-by: Mans Rullgard <mans@mansr.com>

libavcodec/g723_1.c

@@ -283,12 +283,8 @@ static int scale_vector(int16_t *dst, const int16_t *vector, int length)
     max   = FFMIN(max, 0x7FFF);
     bits  = normalize_bits(max, 15);
 
-    if (bits == 15)
-        for (i = 0; i < length; i++)
-            dst[i] = vector[i] * 0x7fff >> 3;
-    else
-        for (i = 0; i < length; i++)
-            dst[i] = vector[i] << bits >> 3;
+    for (i = 0; i < length; i++)
+        dst[i] = vector[i] << bits >> 3;
 
     return bits - 3;
 }