Apply suggestions from code review

Co-authored-by: Philipp Storz <philipp.storz@bareos.com>

CHANGELOG.md

@@ -17,6 +17,7 @@ and since Bareos version 20 this project adheres to [Semantic Versioning](https:
 - fixed bug when user could enter wrong dates such as 2000-66-100 55:55:89 without being denied [PR #707]
 - fix volume-pruning to be relyable on all test platforms [PR #761]
 
+
 ### Added
 - added reload commands to systemd service [PR #694]
 - Build the package **bareos-filedaemon-postgresql-python-plugin** also for Debian, Ubuntu and UCS (deb packages) [PR #723].

core/cmake/BareosSetVariableDefaults.cmake

@@ -661,10 +661,10 @@ endif()
 
 execute_process(
   COMMAND "ls ${changer-device0}"
-  RESULT_VARIABLE exists
+  RESULT_VARIABLE changer_device0_exists
   OUTPUT_QUIET ERROR_QUIET
 )
-if(NOT exists)
+if(NOT changer_device0_exists)
   message(STATUS "Could not find changer-device \"${changer-device0}\"")
   set(error_changer0 TRUE)
 endif()
@@ -680,10 +680,10 @@ endif()
 foreach(device ${tape-devices0})
   execute_process(
     COMMAND "ls ${device}"
-    RESULT_VARIABLE exists
+    RESULT_VARIABLE tape_device_exists
     OUTPUT_QUIET ERROR_QUIET
   )
-  if(NOT exists)
+  if(NOT tape_device_exists)
     message(STATUS "Could not find tape-device \"${device}\"")
     set(error_tape_devices0 TRUE)
   endif()