sigproc: Fix missing 8-PSK tail symbols

Agilent E4406A measurement of TSC synchronized RF envelope measurement.
showed failing power levels at the tail end of EDGE bursts. Regression
traced back to following commit.

Commit d2b070369d
"uhd: Correct timing alignment in 8-PSK and GMSK downlink bursts"

In the patch, the EDGE burst was delayed one symbol, but erroneously
truncated at the tail end causing the failing RF envelope measurement.

The missing tail symbol did not appear to affect end-to-end EGPRS tests.
This patch corrects the truncation.

Signed-off-by: Tom Tsou <tom.tsou@ettus.com>

Transceiver52M/sigProcLib.cpp

@@ -956,7 +956,7 @@ static signalVector *shapeEdgeBurst(const signalVector &symbols)
 
   /* Delay burst by 1 symbol */
   burst_itr = burst->begin() + sps;
-  for (size_t i = 0; i < nsyms - 1; i++) {
+  for (size_t i = 0; i < nsyms; i++) {
     float phase = i * 3.0f * M_PI / 8.0f;
     Complex<float> rot = Complex<float>(cos(phase), sin(phase));