[fix] searchcount's extension

autoload/airline/extensions.vim

@@ -439,7 +439,7 @@ function! airline#extensions#load()
     call add(s:loaded_ext, 'cursormode')
   endif
 
-  if get(g:, 'airline#extensions#searchcount#enabled', 1) && exists('*searchcount')
+  if get(g:, 'airline#extensions#searchcount#enabled', 1)
     call airline#extensions#searchcount#init(s:ext)
     call add(s:loaded_ext, 'searchcount')
   endif

autoload/airline/extensions/searchcount.vim

@@ -4,6 +4,9 @@
 
 scriptencoding utf-8
 
+if !exists('*searchcount')
+  finish
+endif
 
 function! airline#extensions#searchcount#init(ext) abort
   call a:ext.add_statusline_func('airline#extensions#searchcount#apply')