patch 8.0.0292: the stat test is a bit slow

Problem:    The stat test is a bit slow.
Solution:   Remove a couple of sleep comments and reduce another.

src/testdir/test_stat.vim

@@ -4,17 +4,17 @@ func Test_existent_file()
   let fname = 'Xtest.tmp'
 
   let ts = localtime()
-  sleep 1
   let fl = ['Hello World!']
   call writefile(fl, fname)
   let tf = getftime(fname)
-  sleep 1
   let te = localtime()
 
   call assert_true(ts <= tf && tf <= te)
   call assert_equal(strlen(fl[0] . "\n"), getfsize(fname))
   call assert_equal('file', getftype(fname))
   call assert_equal('rw-', getfperm(fname)[0:2])
+
+  call delete(fname)
 endfunc
 
 func Test_existent_directory()
@@ -32,12 +32,19 @@ func Test_checktime()
   call writefile(fl, fname)
   set autoread
   exec 'e' fname
+  " FAT has a granularity of 2 seconds, otherwise it's usually 1 second
+  if has('win32')
     sleep 2
+  else
+    sleep 1
+  endif
   let fl = readfile(fname)
   let fl[0] .= ' - checktime'
   call writefile(fl, fname)
   checktime
   call assert_equal(fl[0], getline(1))
+
+  call delete(fname)
 endfunc
 
 func Test_nonexistent_file()

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    292,
 /**/
     291,
 /**/