Remove duplication of test/assertion counting

Now #mrbtest and #_run focus on the different ways the report their
tests more than how tests get run.

This also fixes a bug in #mrbtest where there was a variable typo
"@test_cound".

mrblib/mtest_unit.rb

@@ -441,13 +441,8 @@ def mrbtest
       suites = TestCase.send "test_suites"
       return if suites.empty?
 
-      @test_cound, @assertion_count = 0, 0
-
       results = _run_suites suites
 
-      @test_count      = results.map{ |r| r[0] }.inject(0) { |sum, tc| sum + tc }
-      @assertion_count = results.map{ |r| r[1] }.inject(0) { |sum, ac| sum + ac }
-
       $ok_test += (test_count.to_i - failures.to_i - errors.to_i - skips.to_i)
       $ko_test += failures.to_i
       $kill_test += errors.to_i
@@ -474,13 +469,8 @@ def _run_tests
       puts "# Running tests:"
       puts
 
-      @test_count, @assertion_count = 0, 0
-
       results = _run_suites suites
 
-      @test_count      = results.map{ |r| r[0] }.inject(0) { |sum, tc| sum + tc }
-      @assertion_count = results.map{ |r| r[1] }.inject(0) { |sum, ac| sum + ac }
-
       t = Time.now - start
 
       puts
@@ -498,7 +488,14 @@ def _run_tests
     end
 
     def _run_suites suites
-      suites.map { |suite| _run_suite suite }
+      @test_count, @assertion_count = 0, 0
+
+      results = suites.map { |suite| _run_suite suite }
+
+      @test_count      = results.map{ |r| r[0] }.inject(0) { |sum, tc| sum + tc }
+      @assertion_count = results.map{ |r| r[1] }.inject(0) { |sum, ac| sum + ac }
+
+      return results
     end
 
     def _run_suite suite