test: vinyl/recover fails on dump counter check

On high loaded host the test vinyl/recover failed on waiting loop
for the dumper counter check. It expected that the value should be
equal to "2" exactly, while on the high loaded host the dump could
be already run more times and the counter value found to be "3" or
even bigger values. To fix it the counter value check was changed
from the exact value to the range bigger or equal of the expecting
value. The error message before the fix was:

[003] --- vinyl/recover.result	Mon Jul 15 10:46:00 2019
[003] +++ vinyl/recover.reject	Mon Jul 15 10:58:10 2019
[003] @@ -517,7 +517,7 @@
[003]  ...
[003]  test_run:wait_cond(function() return pk:stat().disk.dump.count == 2 end)
[003]  ---
[003] -- true
[003] +- false
[003]  ...
[003]  sk:stat().disk.dump.count -- 1
[003]  ---

Closes #4345

test/vinyl/recover.result

@@ -515,7 +515,7 @@ box.snapshot()
 for i = 1, 1024 do s:update(1, {{'=', 3, string.rep('x', 1024)}}) end
 ---
 ...
-test_run:wait_cond(function() return pk:stat().disk.dump.count == 2 end)
+test_run:wait_cond(function() return pk:stat().disk.dump.count >= 2 end) or pk:stat().disk.dump.count
 ---
 - true
 ...

test/vinyl/recover.test.lua

@@ -181,7 +181,7 @@ s:insert{1, 1, 1}
 box.snapshot()
 
 for i = 1, 1024 do s:update(1, {{'=', 3, string.rep('x', 1024)}}) end
-test_run:wait_cond(function() return pk:stat().disk.dump.count == 2 end)
+test_run:wait_cond(function() return pk:stat().disk.dump.count >= 2 end) or pk:stat().disk.dump.count
 sk:stat().disk.dump.count -- 1
 
 test_run:cmd('restart server test with args="1048576"')