replace protoview pa table hotfix with proper code

by thedroidgeek in protoview repo in PR 15

signal_file.c

@@ -45,14 +45,21 @@ bool save_signal(ProtoViewApp* app, const char* filename) {
                 custom,
                 "Custom_preset_module: CC1101\n"
                 "Custom_preset_data: ");
-            for(int j = 0; regs[j]; j += 2) {
+
+            /* We will know the size of the preset data once we reach the end
+             * of the registers (null address). For now it's INT_MAX. */
+            int preset_data_size = INT_MAX;
+            bool patable_reached = false;
+            for(int j = 0; j <= preset_data_size; j += 2) {
+                // End reached, set the size to write the remaining 8 bytes (PATABLE)
+                if(!patable_reached && regs[j] == 0) {
+                    preset_data_size = j + 8;
+                    patable_reached = true;
+                }
                 furi_string_cat_printf(custom, "%02X %02X ", (int)regs[j], (int)regs[j + 1]);
             }
-            // Add patable
-            furi_string_cat(custom, "00 00 C0 00 00 00 00 00 00 00 ");
-            //size_t len = furi_string_size(file_content);
-            //furi_string_set_char(custom, len - 1, '\n');
-            furi_string_cat(custom, "\n");
+            size_t len = furi_string_size(custom);
+            furi_string_set_char(custom, len - 1, '\n');
             furi_string_cat(file_content, custom);
             furi_string_free(custom);
         }