use a shorter name for sources in debuginfo rpms

have the same path as in source rpms, don't build them differently

cmake/cpack_rpm.cmake

@@ -39,6 +39,7 @@ ELSE()
   SET(CPACK_RPM_FILE_NAME "RPM-DEFAULT")
   OPTION(CPACK_RPM_DEBUGINFO_PACKAGE "" ON)
   MARK_AS_ADVANCED(CPACK_RPM_DEBUGINFO_PACKAGE)
+  SET(CPACK_RPM_BUILD_SOURCE_DIRS_PREFIX "/usr/src/debug/${CPACK_RPM_PACKAGE_NAME}-${VERSION}")
 ENDIF()
 
 SET(CPACK_RPM_PACKAGE_RELEASE "1%{?dist}")
@@ -275,7 +276,6 @@ IF(CMAKE_VERSION VERSION_GREATER "3.9.99")
 SET(CPACK_SOURCE_GENERATOR "RPM")
 SETA(CPACK_RPM_SOURCE_PKG_BUILD_PARAMS
   "-DRPM=${RPM}"
-  "-DCPACK_RPM_BUILD_SOURCE_DIRS_PREFIX=/usr/src/debug/${CPACK_RPM_PACKAGE_NAME}-${VERSION}"
   )
 
 MACRO(ADDIF var)