ue: store new EARFCN in the foreground of cell_select to avoid race conditions with the other cmd_worker

srsue/src/phy/phy.cc

@@ -299,6 +299,10 @@ bool phy::cell_select(phy_cell_t cell)
     // Update PCI before starting the background command to make sure PRACH gets the updated value
     selected_cell.id = cell.pci;
 
+    // Update EARCN before starting the background task to make sure is taken into account when finding carriers to
+    // measure inter-frequency neighbours (see set_cells_to_meas)
+    selected_earfcn = cell.earfcn;
+
     // Indicate workers that cell selection is in progress
     common.cell_is_selecting = true;