g723_1dec: inline normalize_bits() in scale vector and optimize it.

many branches and cases of scale_vector are irrelevant for the case here
and by inlining they can be reliably removed.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/g723_1.c

@@ -257,7 +257,8 @@ static int scale_vector(int16_t *dst, const int16_t *vector, int length)
     for (i = 0; i < length; i++)
         max |= FFABS(vector[i]);
 
-    bits  = normalize_bits(max, 15);
+    bits= 14 - av_log2_16bit(max);
+    bits= FFMAX(bits, 0);
 
     for (i = 0; i < length; i++)
         dst[i] = vector[i] << bits >> 3;