Fix fixed point builds of spandsp, and improve logging of modem performance during tests

libs/spandsp/src/spandsp/v17rx.h

@@ -209,6 +209,12 @@ working only on the most optimal lines, and being widely usable across most phon
 TCM absolutely transformed the phone line modem business.
 */
 
+#if defined(SPANDSP_USE_FIXED_POINT)
+#define V17_CONSTELLATION_SCALING_FACTOR        1024.0
+#else
+#define V17_CONSTELLATION_SCALING_FACTOR        1.0
+#endif
+
 /*!
     V.17 modem receive side descriptor. This defines the working state for a
     single instance of a V.17 modem receiver.

libs/spandsp/src/spandsp/v22bis.h

@@ -48,6 +48,12 @@ or 1200bps if one or both ends to not acknowledge that 2400bps is OK.
 #if !defined(_SPANDSP_V22BIS_H_)
 #define _SPANDSP_V22BIS_H_
 
+#if defined(SPANDSP_USE_FIXED_POINT)
+#define V22BIS_CONSTELLATION_SCALING_FACTOR     1024.0
+#else
+#define V22BIS_CONSTELLATION_SCALING_FACTOR     1.0
+#endif
+
 enum
 {
     V22BIS_GUARD_TONE_NONE,

libs/spandsp/src/spandsp/v27ter_rx.h

@@ -44,6 +44,12 @@ at the start of transmission, which makes the design of a V.27ter receiver relat
 straightforward.
 */
 
+#if defined(SPANDSP_USE_FIXED_POINT)
+#define V27TER_CONSTELLATION_SCALING_FACTOR     1024.0
+#else
+#define V27TER_CONSTELLATION_SCALING_FACTOR     1.0
+#endif
+
 /*!
     V.27ter modem receive side descriptor. This defines the working state for a
     single instance of a V.27ter modem receiver.

libs/spandsp/src/spandsp/v29rx.h

@@ -118,6 +118,12 @@ scrambler register) cannot be trusted for the test. The receive modem,
 therefore, only tests that bits starting at bit 24 are really ones. 
 */
 
+#if defined(SPANDSP_USE_FIXED_POINT)
+#define V29_CONSTELLATION_SCALING_FACTOR        4096.0
+#else
+#define V29_CONSTELLATION_SCALING_FACTOR        1.0
+#endif
+
 #if defined(SPANDSP_USE_FIXED_POINT)
 typedef void (*qam_report_handler_t)(void *user_data, const complexi16_t *constel, const complexi16_t *target, int symbol);
 #else

libs/spandsp/src/v17rx.c

@@ -202,10 +202,11 @@ SPAN_DECLARE(int) v17_rx_equalizer_state(v17_rx_state_t *s, complexf_t **coeffs)
 {
 #if defined(SPANDSP_USE_FIXED_POINT)
     *coeffs = NULL;
+    return 0;
 #else
     *coeffs = s->eq_coeff;
-#endif
     return V17_EQUALIZER_LEN;
+#endif
 }
 /*- End of function --------------------------------------------------------*/