prach_worker: move variable to function body

the variable was only used inside the run_tti() function
and isn't needed elsewhere. refactor therefore.

srsenb/hdr/phy/prach_worker.h

@@ -45,7 +45,7 @@ public:
 
 private:
   uint32_t cc_idx             = 0;
-  uint32_t prach_nof_det      = 0;
+
   uint32_t prach_indices[165] = {};
   float    prach_offsets[165] = {};
   float    prach_p2avg[165]   = {};

srsenb/src/phy/prach_worker.cc

@@ -128,6 +128,7 @@ int prach_worker::new_tti(uint32_t tti_rx, cf_t* buffer_rx)
 
 int prach_worker::run_tti(sf_buffer* b)
 {
+  uint32_t prach_nof_det = 0;
   if (srslte_prach_tti_opportunity(&prach, b->tti, -1)) {
     // Detect possible PRACHs
     if (srslte_prach_detect_offset(&prach,