cmake: Fix elseif() without conditions

cmake/os-specific.cmake

@@ -13,6 +13,6 @@ elseif(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
 elseif(CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
   # FreeBSD specific flags
   include(${OS_SPECIFIC_DIR}/freebsd.cmake)
-elseif()
+else()
   message(FATAL_ERROR "Unsupported system: ${CMAKE_SYSTEM_NAME}")
 endif()

utils/kamcmd/CMakeLists.txt

@@ -8,7 +8,7 @@ set(KAMCMD_CUSTOM_NAME
 
 if(NOT KAMCMD_CUSTOM_NAME)
   set(NAME "kamcmd") # Hardcoded name if empty
-elseif()
+else()
   set(NAME "${KAMCMD_CUSTOM_NAME}")
 endif()